You can cleanse it off and I believe you keep the stats. Also might still work with shattering the equip, can't remember.
The entire point of Cocoon is that it gives stats, but it leaves you vulnerable on your opponent's turn. So no.
That was not always "the point." It used to be 2 turns. Equips don't have to have negative effects. Please come up with a better argument.
Cocoon is an 8 nora ability, which gives 14 nora in stats. Doesn't need to be changed. Forest's Embrace is a 30 nora equip, which gives 26 nora in stats and abilities. It's already good.
You can shatter forests embrace on the turn it is equipped, keep stats, and gain AP on your next turn
As far as I can remember Cocoon has always been 3 turns. It currently isn't an amazing equip but is sufficiently decent. It is pretty good in a deck with Experimental Warspirit since Loss of Life goes through Cocooned (use it as a negative equip). Of course, that is not the use it was designed for but is probably the most useful use.