I have no clue what to get Hierarchy and Bubz. And I'm pretty sure that I got Alan the right gift but it makes a different sound from everyone else so I'm not sure.
Alan want different gifts each time you played the game. You just need to talk to AimiMay and she'll give you hints on what to get for Alan.
For Hierarchy, trust me, at the house, go to right and click on the computer. Then click profile on top left and click Hierarchy's profile on bottom right. There you can see his one and only wish list.
I'm unsure for Bubz so that's that. There is Alan's lil quest to complete. But the thing is that, idk where the heck am I going to find that person to help and give hint on what gift to get for AimiMay.