I know the point of going tubeless is getting away with running lower pressures with people saying running at 25psi is pretty normal, but I'm interested how high you can realistically go? Like for the road, for drops where lower pressures make your landing more sketchy and for the heavier rider already using high pressures offroad with big tyres?
(I've run 55-60psi in a 2.5" High Roller with freeride tubes before, because they pinch flatted at 50psi on the rear, twas the alps though)

Also, especially the front, as well as a low pressure tyre potentially being a bit sketchy on landing drops/jumps, do you not loose some steering precision?

I've run 50-psi in a rear with a folding bead that fits fairly loosely on the rim. The tube provides no help in holding the tyre onto the rim (other than initial seating) so there should be no difference in the pressure it can hold over normal.

I read somewhere that ghetto tubeless doesn't work well (safely) at higher pressures is all

I had some Hutchingson bulldogs blow off the rims at 40psi! Scared the bejesus out of me as I was pumping air at the time during inital seating of tyre whilst ghetto'ing.

Max pressure for them on further reading was only 35-40 psi I think?

I woin't be putting my current tyre anywhere near full recommended pressure for fear of it blowing off the rims and damaging them.

Totally dependant on the tyre I'm afraid…

Some tyres have such a loose bead they won't seal at all. Some are so tight I'd not hesitate to run them at their max rated pressure if the need arose!

It's down to a bit of experimentation sadly, but the rule of thumb is that if it seemed a bit easy to go onto the rim, and was dificult to inflate, be wary of running high pressures. Whereas if it was a nightmare to get on, but pumped up easily, then puff it up til your heart is content!