Not quite for 2 and 3; we also need more of the Default Conditions, which answer some of the questions alone:
● Targets must be “in play.”
● An ability that returns “all enhancements” (or “all good enhancements” or “all evil enhancements”) from battle targets all enhancements played on the same side of the battle as the card with that ability
The second part answers your question about "which evil enhancements:" it is all
on the same side as Momentum Change is played. It is
not all of the EE in battle, just on that side.
As far as the first question, Praeceps is correct, as it is a delayed trigger that tells you that something happens to the cards that were played rather than them going to the discard pile (thus it happens in Battle Resolution).
Lastly, in regards to which hand cards go to, they
always go to
owner's hand with a Return To Hand ability, as it states in the General Description (otherwise it is a Take). That part of the General Description should probably be a "default condition" instead, with the General Description reading "A return to hand ability puts a card into a hand." We'll discuss that.
