A lot of people on this site would love to have your problem. So many can't get near their birds and are constantly working at it.
Bob is much like Yoshi and I have to be the mom sometimes and tell him not right now little man and go and do something else.
Animals really do learn by repetition and the pavlov dogs theory is true. If every time Yoshi begs to come out and sit on your shoulder and you let him, that is teaching him to beg because it pays off to beg, he gets what he wants.
If your truly asking if his behavior is to excess, only you can answer that question. If you have concerns about leaving him for school and Yoshi having issues with it, you need to change your relationship slowly now.
I think any animal needs boundries, whether it is behavioral, social or diet, you have to do whats right by the bird. I have a hard time not giving too many treats because Bob begs for them, but I have learned to let it go and Bob does just fine.
Yoshi needs you and toys and good food and water and sleep and on and on.... if he is out of balance by too much of any one thing that is what we call overindulgence.
I think he needs a balance of activity and time to play by himself too, but that is just me. I may be completely wrong about this but I want to be happy having a bird, not burdened by its demands.
I am sure you will get much better input than I gave, but it all depends on what you want in the long haul.