1. Did the Klingons or Romulans help in the end? was there any confirmation of that?
2. Where did the escape pods of ships like the Saratoga do if the entire fleet was destroyed??
Hanson said the Klingons were sending warships to help, but there's no evidence that they made it in time. No Klingon wreckage was seen in BOBW and no Klingon vessels were seen in "Emissary." There was an issue of Marvel's
Voyager comic book in which
Voyager encountered Wolf 359 survivors who came through a space-time rift, and its depictions of the battle included Klingon ships, but that seems to conflict with the canonical evidence.
So my guess would be that the answer to your first two questions is the same: the Klingons sent warships, but they probably didn't arrive until after the battle, in which case they would have been the ones who retrieved the escape pods.
3. Not really W359 but in same area....why was the "Mars defense perimeter" three nats?
Because that's all the producers could afford to show. It's easy enough to assume those shots were just a sampling of a more extensive battle.