After the 5 years you will be given the option to fix it, or go with variable or tracker. It is impossible to say whether it will be more or less than now, it depends on the interest rates at the time.
Life insurance - If you've no dependants, I'd stick with going with the minimum to cover the mortgage. Anything extra would just go to your estate.
Look up on serious illness versus income protection. I got my place on my own and it was, and still is, something that concerns me.
Best of luck - Dem