One thing I feel I need to add to this thread. I'm in no way an expert at any herp stuff yet but I do know that the "surge protector" you posted is nothing more than a power strip. If there is any power surge in your place then that thing isn't going to do a thing to stop it. You need an ACTUAL surge protector with a good joule rating and that will kill itself for the greater good if it gets overloaded. I know most good tstats have fuses that'll blow in a surge but do you really want to chance it? You can get good Cyberpower surge protectors from places like newegg.com for $20 at most and they'll do the job just fine.

Also, did you wire your heat tape in sequence with some 12 gage wire or did you just do a bunch of individual plugs? I'm guessing the former.