I have played when I am very tired. to your point playing well rested in the right move. I'm sure that i have had some good results while tired but I am sure that overall it's a losing play.
All in is the most polarizing play in poker. It has multiple purposes and I love seeing how it plays out. More often than not it leads to your opponents fold. You have to be very strong or have very good odds to call.
You can, dare I say should, be more aggressive. With fewer players/cards dealt the more strength your hand has. A weak hand like AT or 55 has much more value with fewer cards in play.
I am opening every A or pair and 3 betting them often as well.
I believe that you hsve the same percentage of good and bad players at all stakes. Just because you have money doesn't mean you're good. The same thought process can be applied to players who may not have much money to play with.
I find HU is more of a who blinks first game than a test of actual poker skill. With that said plenty of the biggest bankrolls in the world come from HU games.
It's an oversaturated market for sure. Players often have a few go to sites already. Hard to convince players to try something new when they have reliable options.