Yes, I agree that you should do a search. Include one on the honda forums as part of your efforts.
As to the questions, the Kawi 900 Custom looks smaller than the Kawi 900 Classic. If looks are really your issue, only you can answer.
At 30 pounds difference, or 5%, I'm not sure one would notice. Once you were used to riding one particular bike.
IMHO, Fuel Injection vs Carb is HUGE !!!!
The e10 fuel is havoc on carb engines, of all types. This pertains to plastic inside in the construction of carbs in particular. With the fight on by the corn farmers to make the fuel e15, stay away from carb engines.
The problems with boats and jet ski's are already legend. As the off-season in much shorter for MC, the "problem" is handled without the uproar of other power sports. But, be certain that this is a huge issue.