Can silpat be used in place of parchment paper?
Definitely. I like Silpat better for lace cookies and Florentines, but in a one-thing-on-a-deserted-island contest, parchment would win: I couldn't steam halibut with lemon and chives in Silpat.
Depends on what you're doing. If your baking and intend to use as a liner, it works fine, just keep it in the temp range.