Mike
I think it is possible to go over board, of course if you are that unsure then the thermometer is the best way forward for you.
As you long as you ensure that any food you intend to freeze isn't sitting about after its cooked and then sealed and frozen properly, you will minimise any bacteria build up. When you come to re-heat it, just make sure its hot all the way through.
I buy cheap take-away style foil trays with the card tops. I fill one of these up and seal the lid on. Once cool enough I freeze it. Upon reheating, I simply take it from the freezer and pop it in the oven. The oven is then turned on to heat at 150c and the timer set for an hour. I have never had any problems doing this and the food is always piping hot all the way through. No need to thaw it either.