Correct me if I'M wrong we're currently discussing two problems:
1) Wizard flavor: you want more, like specialist wizards
2) Wizards dealing damage: you don't want low level wizards to be good at it in any way (at-wills and crossbows are too good) for a prolonged period i.e several encounters on one day.
I'm not so much looking for magic-users to have a minimal impact, I'm looking for them to have a flavorful and balanced impact on their society. Rather than having generic wizards with their generic at-will damage spells doing their best impersonation of mystical crossbowmen, I'd like to see wizards being much more unique and diverse. If they study and focus on a particular school, it should define their use of magic (but not restrict soley to that school.) An Abjurer should feel different from a Transmuter and a generalist wizard. Each will have an impact on their local communities in different ways.
You say you don't want a
generic wizard but you have no problem with various specialist wizards and
generalist. I'm confused.
B/c I believe your main complaint about wizards goes more along the lines of your following statement.
I like at-wills. I think they serve an important purpose in the game. What I don't like is at-will that cause damage at low levels. I want the wizard and cleric to be able to impact battles magically and I believe it can be accomplished without turning them into turrets, either with crossbows or damaging at-wills.
I assume you mean wizard/cleric at-wills. Why should they have to resort to the so called MBA/RBA (using 4E terms) while fighters, rangers, rogues, etc. have still at-will powers.
Furthermore, if the wizard should not use spells or ranged weapons e.g. crossbows what is he suposed to do after casting his daily/Vancian spells?
Maybe you would be more happy if the wizard had to make a casting roll/check to use his at-wills or something similar - so using them entails a risk, fumble - his attacks can fail potentially at two/three instances: casting roll + attack roll and/or save.
What I really want to know is what should a low level wizard do in combat, prolonged combat (8+ rounds) or in the fourth encounter on the same day?
And while you write your answer think about how playing such a character would feel for you? And what might other people think about the feel especially players coming frpm 4E?