1) does Infiltrate effectively give a poor-man's "phasing" to a figure, ie they don't need to roll breakaway from one enemy fig--but need to be adjacent to another enemy fig at the end of that movement?

2) please explain how Improvise works. a bit confused on this one. (do i declare to use Perplex to up a friendly fig's value, then say i'm going to place a token on the card instead? sounds....weird).

thx.

1) does Infiltrate effectively give a poor-man's "phasing" to a figure, ie they don't need to roll breakaway from one enemy fig--but need to be adjacent to another enemy fig at the end of that movement?

With Infiltrate, you would not automatically break away, a roll would still be needed.. The card simply says you ignore opposing characters for movement purposes, like a flier. You do need to end your movement next to an opposing character, though.

2) please explain how Improvise works. a bit confused on this one. (do i declare to use Perplex to up a friendly fig's value , then say i'm going to place a token on the card instead? sounds....weird).

With Improvise, I think the "chosen character" is the figure who the card is played on. Each round, instead of using Perplex to up a combat value on this figure, you would instead place a token on this card. If this character misses an atack roll but the result is doubles, and you have three tokens on this card, the roll would hit instead.
It's another in the growing line of Opportunist, Contingency Plan, Streak of Luck type of cards.

do close-combat and range-combat expert 'modify' your damage? so you could choose not to use either of those, and add a token?

i would say no because you have to give the character a power action to activate those,

im not an expert by any means but thats just my take

but im sure things like AIM and PD (that ups your attack at range) can be used every turn because you ar still upping the attack.

also the new sheild's range +1 could be used on each turn.

my question is could you pull one off contingency plan and put it right on improvise?

and what about enhancement?

Well, let' look at the wording:

Choose a character. Once per round, when one of the character's combat values would be modified such that the modified value is higher than the unmodified value, you can ignore the modifier and put an Improvise token on this card, if there are fewer than three tokens on the card. If there are three tokens on this card when the character makes an unsuccessful attack roll where the result of the roll is doubles, you can remove all tokens from this card and automatically hit the target of the attack (though this is not a critical hit). Remove all tokens from this card when the character makes a critical hit.

It states simply that when a combat value would be modified up, you can instead place a token on this card. CCE and RCE are indeed modifications, so I would say that yes, it would work with these powers. You would not use the CCE or RCE and get the token instead. It also makes sense because these two powers are pre-reqs for the feat.