1 - YES!!! How would the assignor know unless people tell him?
2 - Well, yes, get through the game, but there are MANY umpires who are not that "good", and if I start picking and choosing who I will work with again based upon the criteria you listed above, that list would be quite small. Really. MOST umpires at the amature level have one of more of the above problems! I guess your best policy is to never say never! You never know if that guy will move above you!
3 - Yes. Indeed, I have had many guys not take the critisism too well, but that is THEIR problem. I leave myself open to critisism, and ask my partner to discuss even VERY SMALL details about the job I do. If they think my hands look funny at my side in between pitches, I want to know about that so I can get some more opinions and possibly change what I do with my hands. Anyway, I don't expect most people that I work with to wish to be the best umpire they can be, but, no matter what, they should at least be receptive to hearing about what I felt they are not doing so well, and if some of the critisism is severe, all the better! They got paid just as much as I did to do that game, and they should SERVICE the game to the best of their abilities. If their abilities are limited, then I have just given them ideas on how to increase their abilities! I will not pussy foot around with critisism. If my partner sucks, I may not say "You suck, and here is why", but I am for sure going to talk about major, important problems they displayed as an umpire.
1st and 2nd year umpires, I cut them a lot of slack. Even up through about the 4th or 5th year, I try to not get too picky about the little details. But after that, I think sticking around for more than 4 or 5 years means you want to pursue this advocation at a higher level, and thus, you SHOULD be open to senior umpires doing detailed critiques about your work!