I'm OK with one minute rounds, since I see the "to hit" roll as a roll to determine if you scored a hit that would kill an ordinary human. Hit points then become the ability to ignore fatal blows. I'm also OK with some of the shorter time units, like 10-second rounds, since it's still possible to have made multiple actions in that time period; I'm not so enamored of really short combat rounds, like TFT's 5 second turns or the GURPs 1 second turn.
I'm not as worried about the varying definitions of "turn", because in my mind, the turn is not a fixed time unit, but standard game/sports terminology: I take a turn and do something, then you take your turn, and when all other players have taken a turn, I get another turn. The amount of time that passes depends on what kinds of action we're doing.
For the purpose of explaining rules, it might be clearer to specify different kinds of turns: combat turns, exploration turns, or even travel turns for overland wilderness journeys. I think the best solution for me is to use 10 second combat turns, 10 minute exploration turns, and 4 hour travel turns, not because of any specific realism need, but because these work out to:
- combat turn = 1/6th of a minute
- exploration turn = 1/6th of an hour
- travel turn = 1/6th of a day
Characters must rest 1 turn for every 5 turns of activity; if they can't rest (because they are in combat, being pursued, or on a forced march,) they're at a disadvantage and might have to make a save or lose 1 hp. This means that, for overland travel, characters need 4 hours sleep every day, plus they must spend 1 turn to make camp and 1 turn to break camp, normally; normal travel time is thus 3 turns or 12 hours.