No I don't , take the tyres off and weigh them if you need a tyre change ? Tyres add weight also If you are looking for unsprung weight?
I do not know. Generally i am considering forged alu like oz, marchesini, dymag or even original r model or carbon like bst. But carbon are much more expensive.
Yes you will mate, light wheels are one of the best mods you can do, all my bikes have them and I'm currently looking for some for my track bike.
I got some Marchesini forged wheels off a HM1100S to fit to my M1100S. The front wheel is identical to a 749. Measured weights - with 120/70 Supercorsa, no discs: Standard 8.45kg Forged 7.35kg