Ok, I checked wiki but not to detailed from what I read.
Fate points, and unlocking the twists. Lets say I unlocked one. Does that unlock it for every tree I would switch to? For instance would it be unlocked for LD and Flowers, and any other one I made active?
Second the choices made when twisting. Do they stay there for any tree I change to? Say I slapped sense weakness in the first box. Would it be there in the same box no matter what tree (shadow, fury, LD, Unyielding) I made active?
And 3rd can you change up twists indefinitely, or you you have to reset em like the tree?
The level belongs to the slot, so if it is a Tier X slot then it can take any Tier X or lower ability that you activated while in that destiny. So the answer to the first question is yes.
(This doesn't guarantee that the twist will actually be useful. Look out for weasel words like "while in such-and-such stance" or "if alignment is so-and-so." They disqualify a good sized chunk of the abilities from being usefully twisted).
A question you didn't ask but I think you might want to know is no you don't have to twist the prerequisite ability to twist the higher ability. But you do have to have any prerequisite ability active at the same level as the one you want (so if both can be 3/3 then make them both 3/3).
Yes the choices stay there. So there will be cases where you'll want to switch out again when you are on the destiny where the twist came from.
Yes you can change twists ad infinitum as long as you are a VIP in town or are at a fatesinger. You just have to have the Tier that the slot is or lower. Remember, the property of level or tier belongs to the slot--it is content neutral. In addition there is a way to reset the tiers on the slots themselves, but I don't know how since I've never had to.
A couple of things about twists that I didn't realized for a bit:
The fatesinger can clear out your twist tiers and you can reassign them. For example, you can have a 3/3/2 tier selection of twists and have the fatesinger reset them so you can assign a 4/2/1 tier selection. It's free.
You don't have to be in the ED with the ability you want to twist. Just select the Show All box and drag abilities from other EDs that you want to use in your current destiny.