Yeah, the more devices you start linking together (surge protector) the more things could go wrong. With regard to a power outage, there are a number of threads on that subject. Bottom line is, that a power outage is a problem regardless of whether you're using a GFCI or not. You should make provisions for some sort of back up in any case. Maybe some one else who has experienced a power outage with GFCIs can pipe in here and confirm that the GFCI trips??
BTW, shoot me, but I've been slow getting my own power situation in order. I have an older home and not only is my tank currently not wired to a GFCI, but the receptacles running it aren't grounded....!!!! Have to get on that right away, but I have to tear into the wall to fix the whole mess.