Shadow War Armageddon rules questions

In shadow war Armageddon do you need to be able to see some one in order to charge them?

rules quote for ease of reference:

"A fighter is aware of any enemies they can see (see line of sight, pg30) and any enemies that are not hidden and are within a number of inches equal to twice the fighters's initiative"

Bonus question: at the end of your turn if you've been pinned when you get back up can you then hide? (assuming you meet the other requirements such as being in cover)

To answer your questions, you do need to be able to see the target in order to charge as you can charge those that you are "aware" of.

To answer your second question, hiding is done before, during or after movement so long as it is still in that "phase". If you have been pinned, you essentially miss that turn. at most they are allowed to crawl 2 inches. at the end of the turn, they'll be no pinned but the movement phase and such has already passed so no. HOWEVER, if they recover at the start of your phase (e,g they are close enough to a team mate to test to recover and succeed) then they can do everything they could normally do.