I really don't think you are going to get you problem resolved without some pics.
As far as I know the only thing that runs from the parking brake lever to the caliper is a cable, not a hose, and like I said before cables don't leak.
You can get tires foam filled at almost any heavy duty tire shop, I work at a construction equipment dealer and lots of the skid steer tires get foam filled.
It is that expanding foam, but I would think it would be a very harsh ride.
Yes it does sound like the voltage regulator.
However, you should check your harness thoroughly for any problems. You wouldn't want to burn up another regulator if that is the problem.
Here is a funny ad on ebay, read the description.
eBay Motors: Yamaha Blaster 200 Complete Working Bottom End, Motor (item 160299209652 end time Nov-23-08 19:02:35 PST)
More proof you should always do your homework before buying parts, you may end up with a stinky!
I had a cherry 87 CRX that I custom painted, rims, double barrel webber carb, custom body kit, then I used it to mow down a deer coming home from work one day.
I don't spend any time or money upgrading my cars now.
I think you are saying the hose is leaking, a cable absolutely does not have fluid in it (other than lubricant) If the hose is leaking it needs to be replaced.
A pic would help satisfy any further speculation.
I am 6'1, 200 lbs and the only problem I have is with the front fenders.
I also have a z50r, and a little 110cc chinese atv and I have as much fun on those as anything else. So, just because you might be a little big doesn't mean its not fun.