I used to be C, then around half way through 3.5 I switched to A...
Does your username have something to do with that?

I'm pretty lenient and let people use spells for different but less powerful effects. E.g. use Cone of Cold to freeze the first few inches of a pond into an ice bridge. I also say that if you have a spell prepared, then you can use a less powerful version of it in a lower spell slot. E.g. If you have fireball prepared and you just want to set a bookshelf on fire, fine, just spend a 1st level spell slot and it erupts into flame.
Out of combat, I let casters do all sorts of things that are within their niche and tropes. For instance a diviner can use some divination to help the farmer pick the right wife, or tell a woman the sex of his unborn child. There are no spells for that sort of stuff, at least not at low levels, but it is something you expect a diviner to be able to do. We had a level 9 priest of a harvest god who could bless a villages crops and see them have a bumper harvest. We had a Satyr bard who was a 'priest' of the goddess of festivals, I let him turn water into wine during a religious celebration. I tend to hand wave a lot of stuff for non-casters too.
Magic Missle is a tricky one, as it is unerringly accurate. Casting it to hit the chain on the amulet around the lich's neck, or hitting the rope of the chandelier etc seem reasonable but becomes very powerful. Why can't you just hit the enemy in the eye every time if you can do that? What about hitting the top of a lever on the other side of a portcullis and pushing it down. That seems reasonable too. It becomes a very good utility spell that mimics a more powerful magehand if you let it be that accurate.