British Embassy: They'll give you the originals back once they've sighted them.
With regards the situation for your Marriage License and Birth Certificate, that sounds a little odd. But bear in mind you can get as many "original" birth certificates as you want from the NSO in the Philippines, so it could be true. I'd get her to explain that in England you only get one Birth Certificate, and that's the only original. Or give them a full colour photocopy, and see if they actually notice the difference.
