Something that I forgot to mention that my professor mentioned to me several times and told stories about on almost a daily basis was the fact that his Ruppell's parrot was absolutely a "1-person bird", my professor was definitely his person, and that no other people in his house could get anywhere near him. He used to tell stories all the time in the morning about how his wife was mad and wanted him to rehome the bird because she couldn't get near him if the bird was out of his cage, as the bird would continually dive-bomb her, climb up onto her shoulder and bite her ears and growl, and basically do anything and everything he could do to get her to get away from his person. Once she moved across the room from my professor or to another couch, etc., the bird was fine, but as soon as she sat or stood anywhere near him, the bird would attack her, along with their 2 kids. So they pretty much left the bird in his cage or out free on their sun-porch when people other than the professor were home, and as soon as everyone else left, my professor would then let him out free with him until his wife and kids came home.
I knew another person that worked at the PSU Animal Diagnostic Lab with me years ago that had a Ruppell's parrot, though i didn't talk to her much or see her much, nor did she talk about that bird or any of her birds much at all (she had a Macaw of some kind too, but never spoke about them, they were her husband's birds). Since the birds belonged to her husband prior to them getting married, the Macaw was "okay" with her but not great, and the Ruppell's did the same thing to her that my professor's did when she was near her husband. In-fact, the only story I every heard her tell about the Ruppell's was in the lunch room one day (she worked in the Avian Influenza Lab across the parking lot, I worked in the main building in Animal Virology and Cytology Testing and Research). She was really pissed-off and she said that she wouldn't have married her husband had she known that he "would not willingly get rid of his damn birds", and she explained that the Ruppell's parrot was constantly attacking her and she wanted it gone...you can see why I didn't talk to this woman much at all, not only due to her being in a different department, but we didn't see eye-to-eye about anything at all, and she hated me because I was 22 years old and working in the job that she wanted apparently, as i was told by other people)...
So I don't know if the "1-person" personality is common to all Ruppell's parrots or not, but the only 2 that i have ever had a connection to definitely were not only bonded to only one person, but they attacked anyone and everyone who came near that one person. In contrast, my professor's Ruppell's was totally fine OUTSIDE OF THEIR HOUSE, as he never once became jealous or violent while in my professor's office, though i never got very close to my professor either, lol...
I can tell you that my Senegal is also a 1-person bird, but not to that extent. I am currently single and have not had anyone living with me since i got Kane 2 years ago, but i've not had much of a problem with friends or family being in my house, yet again, no one has really spent a lot of time being very close to me with him out of his cage/room. I don't know how he would react to someone touching me, probably not well, but I don't think kane would respond the way these 2 Ruppell's did.
The thing to remember is that all birds are individuals, just like people are all individuals, each with their own personalities, character traits, and then you also have to consider 50% environment in addition to what nature gives them. SO THE BEST ADVICE I CAN GIVE YOU, WITH ANY BABY BIRD YOU BRING INTO YOUR HOME, IS TO START SOCIALIZING YOUR NEW BABY BIRD FROM DAY #1, AND EVERY DAY FROM THAT POINT ON!!!
The best purchase that you can make BEFORE you even bring your new baby home is an Aviator Harness. They are by-far the safest bird harness/leash available, and since your baby is going to be hand-raised, HOPEFULLY THE BREEDER IS ONE WHO HANDLES THE BABIES EVERY SINGLE DAY, AND WHO TOUCHES THE BABIES ALL-OVER THEIR BODIES EVERY DAY, UNDER BOTH WINGS, ON THEIR BELLIES AND TAILS, ON THEIR LEGS AND FEET, ETC. EVERY SINGLE DAY. Most good breeder do this, and if so, then if you start putting the Aviator Harness on your baby from the day you bring him home and do it at least once every day forward, you'll have no problem getting him trained to be fine while you're putting it on him, while he's wearing it, and while you're taking it off of him.
IN FACT, I WOULD ORDER THE AVIATOR HARNESS IMMEDIATELY, LIKE NOW, AND THEN AFTER YOU CHOOSE A SPECIFIC BABY FROM THE CLUTCH, THEN GIVE/MAIL THE AVIATOR HARNESS TO THE BREEDER AND ASK THEM TO START PUTTING IT ON YOUR BABY ONCE A DAY, LETTING HIM WEAR IT FOR 15-20 MINUTES A DAY, AND THEN HAVE THEM TAKE IT OFF, AND ASK THEM TO DO THIS ONCE A DAY, OR AT LEAST EVERY OTHER DAY. Most good breeders who hand-raise should not have any issue doing this, I have put many a harness and/or Flight Suit on baby budgies and cockatiels I've bred for people. If your breeder is willing to do this for you, then your baby will already be used to putting on and wearing the Aviator Harness by the time you bring him home, and you can start taking him with you in the car, into stores, etc. from the day you bring him home, which is absolutely the best way to socialize him.
I'm going to say this just because I don't know your level of experience owning a parrot, but NEVER, EVER TAKE YOUR BIRD OUTSIDE WITHOUT HAVING A HARNESS ON HIM OR HAVING HIM IN A LOCKING CARRIER, NOT EVEN IF YOU CLIP HIS WINGS!!! Many a parrot with fully-clipped wings has been lost, swept-up by the wind, which makes even a clipped bird able to fly for miles under the right circumstances. I cannot tell you how many pet birds i've seen or heard of being lost because their owner thought it was okay to take them outside with them since they were clipped, and their bird just took off, caught some wind, and were gone, OR EVEN WORSE, A LARGER, WILD BIRD LIKE A HAWK OR RAVEN SWEPT DOWN AND CARRIED THEM OFF, OR A CAT GOT THEM...So always have a harness and leash on him if he's outside or in your car...
Many, many stores allow you to bring your bird inside with you while you're shopping as long as the bird is on a harness and leash. These stores include Petco, Petsmart, and pretty much all other pet stores, Lowes, Home Depot, Sam's Club, and a ton of other stores too...Just yesterday I took Bowie into my local Walmart for the first time with no issues at all, in-fact the employees were in-awe of the fact that i had a parrot on a leash. Bowie learned early about riding around stores either on my shoulder, or better yet on the top of the shopping cart. He absolutely loves to ride around stores while sitting on the metal seat-back of a shopping cart, because he can see everything and everyone, and he gets all kinds of attention. I happened to have him with me yesterday morning for an early hike in the woods/by a local stream, he was wearing his Aviator Harness/leash, and on the way home i had to stop at the grocery store to pick up a few things...I've seen tons and tons of people with dogs on leashes in different Walmarts, at least once a week i see a person with a dog in my local Walmart next to my house, so I thought why not, the worst that can happen is they'll ask us to leave. Lowes and Home Depot are our usual stores to ride around in, as they advertise that all pets on leashes are allowed, I've even taken my Bearded Dragon with me to both of those stores on her harness. But at Walmart all dogs are allowed inside on a leash, which i didn't know, but i googled it when i got home, and apparently they allow "Emotional Support Animals" inside. However, I've never seen any tags or certifications on any of the dogs inside of Walmart, maybe a plain vest to look like they are an ESA, but that's it.
Bowie was a hit, and the elderly lady at the self-checkout was scared to death by him when she saw him move, as she told me that she thought he was a mechanical bird on my shoulder, lol...I don't quite know why i'd have a mechanical bird on my shoulder, on a leash, walking around Walmart, but whatever...Anyway, they all loved him, and everyone wanted to stop and pet him, which he loves. This is because I brought him home at 9 weeks old and started doing this on at least a weekly basis with him and with Kane, the senegal, so that's my best suggestion to you and everyone else who is bringing home a hand-raised baby but is concerned about socializing them...
BTW, my Senegal, Kane, wears an Aviator Harness, size extra-small. I made the mistake of first ordering him a size small, even though the size chart online said that a size small would fit larger birds, i just assumed that an extra small would be too small for a Senegal...wrong! The size small was huge, and would have fit an Amazon! So you definitely want a size extra-small for a Ruppell's