That's a nice looking bike. Myself, I'd like the gas tank farther forward, but I understand it's position based on the shape/style of the top tube.
As for your problem, I agree with the opinions above, replacing a tire isn't very expensive unless you're going into specialty tires. Putting a rear back on is a bit of a juggling act with the two chains, sometimes I drop the master link on the motor chain to make it easier.
When the tire is off, inspect the rim for spokes that have been over tightened and protrude into the rim. If you have any like that, they will pop your tube for you. Adjust with a spoke wrench, or take it somewhere to be adjusted. (Warning, many bike shops will grumble about the rag joint, some may refuse to do anything to it... these are places that do not want your money, so find somewhere else where they think your bike is cool and the 'wrenches' drop their tools to come look at it).
I haven't used Gorilla tape, but I have used both electrical tape and duct tape to line rims with (not on the same rim at the same time). For protection from the outside, I picked up a kevlar-lined Kenda mtn tire from Walmart. In addition to a thick-walled self-sealing tube, I put an older innertube between the tire and the good tube. (Split the old tube all the way around, remove valve stem. When putting it into the tire, fold it over itself until you have a triple ply of old tube between the tire and the good tube. When you inflate, go to 5 psi lower than your sidewall rating to allow for the extra thickness).
I used to ride through a light industrial area to go to and from work, and after doing as I decribed above I reduced my flats from at least weekly to only once in a while.