2 Do not play your hand play your range?
This is a big mistake in micros. Why? Our V under fold in micros so having a balanced range makes no sense. In fact in many spots we should have 0 bluffs as our V will call with 3rd pair so no way could we play range profitably.
Exactly. Even against players, who have perfect GTO strategies,
bluffing is no more than neutral EV, and the only reason, we do it, is to force them to call us with bluffcatchers, when we are betting for value.
But in the micros this is just not relevant most of the time. Before people can start exploiting us by folding
bluff catchers, they need to figure out, that we are never bluffing. This takes a large sample of hands, and in the micros player pools are large, and a lot of opponents are either multitabling or beginners, who can only manage to focus on their own two cards (level 1 thinkers).
In top of that, as you say, they are underfolding in many spots, or at least the recreational players are. So as long as they dont adjust, we increase our winrate by not bluffing in spots, where we think, they are unlikely to fold.
In the micros balance is only important in situations, that occur all the time, and that will show up on peoples HUDs, if such are allowed. If we only 3-bet AA and KK, then HUD-users will figure that out eventually, and then they will start to exploit us by overfolding to our 3-bets. Or if we always fold to 3-bets, they will start attacking us more.
But there is no point in worrying about about having a perfectly balanced range for river check-raising on monotone boards or anything that detailed. And especially not if you play tournaments, where those situations are rare to begin with.