Couple of things:
1) I used sheet metal screws or nuts/bolts/washers (depending on location) on all of the rubber hold downs I've installed. I've had no problems.
2) On my personal car I did only the rear lid (which was fiberglass) and did not use a secondary latch
3) If you choose to remove the secondary latch it's probably a good idea to take out the hood shocks ... at least that way the hood won't "want" to go up.
