There's a whole bunch of things I don't do in my game - usually because I think it's not interesting, slows down play, detracts from the fun or whatever. I realise that my style is not the same as everyone's (I'm sure some people would be horrified!)
Anyway, the following don't have a place in my game:
Encumbrance - too dull. Too tedious.
Money under 1 SP - can't be bothered with CPs and the price of a meal. That's not heroic gaming! Really cheap stuff is just "assumed" in my game. Same goes for basic adventuring equipment (ropes, picks, rations, etc.)
Identify - this one will be the one which most people will disagree with. I don't force players to identify items (unless there's a good plot point involved). Unless it matters to the game, they get all the info on an item (using an Item Card) immediately. I can rationalise by trying to claim that all the knowledge skills and divinations in the party make such a thing easy, but the truth is it's just easier and facilitates play for me. Doing this, IMO, does not detract from the enjoyment of the game, even if it seems unrealistic.
Components - unless it's really expensive, spellcasters are always assumed to have material components.
Anyone else do anything similar? If so, why? Is realism more important to you than smooth gameplay and fun? Is realism more fun for you than for me?