Yep. Alcohol is actually one of the best antiseptics there is, and it should take care of any baddies for you. I don't have any exact data as far as amount, but if you have a gallon ziplock bag full, I personally would go with around a half of a fifth of vodka, then re-blend it briefly (or at least mix very thoroughly).
If you have enough headspace in your fermenter (say, a 6.5-gal carboy for 5 gal of beer) then it probably won't be an issue. However, if you are filling it near the top I would replace the fermlock with a blowoff setup (you should be able to find tubing of the caliber that will fit snugly into the hole in your stopper). The other issue I find with the fermlocks (particularly in plastic fermenters like better bottles when you move them) is that if you are moving to a colder area, the air cools and condenses, creating a suction, which can then pull whatever liquid you have in your fermlock into the beer. Thats why I also use alcohol for the fermlock as well.
I don't know that I would have boiled the fruit at all, let alone twice. For the same reason boiled fruit doesn't sound appetizing in general, I suspect the boiling could affect the proteins in the fruit in an undesirable way, or at least reduce the residual presence of the fruit in the finished product (which may be surprisingly minimal anyway to you, after the yeast have gotten ahold of it). Usually you hear about pasteurizing fruit, but not going as far as boiling. Personally, I think between freezing it and adding the alcohol, that should be more than enough for sterilization. Keep in mind that if you are adding to the secondary (or the primary after primary ferm is complete) then the alcohol content of the beer itself will also be on your side.