It takes about 5 minutes to change that petcock out, after you drain the tank.  Personally seeing how many people have problems with the stock one I'd just change it now, or keep the raptor and a screwdriver/spare fuel canister with you at all times to avoid a fuel related issue leaving you walking the bike home.

 True but my way sounds much more inconvenient.

I did all that.  It turned out to be a leaky seam in the gas tank welds.  'new' dented tank and it runs fine.  not always the obvious.

Be well,

Two words: Red Kote

More than two words:  Red Kote will more than likely seal your original tank for less than you spent on that dented tank.  If your leaking tank isn't dented, and you prefer it to the dented tank, then Red Kote is what you want.  

If you like dented tanks, that's cool too.  The vintage GT185 tank I put on my bike has a few dents, some scratches and a little bit of fading. One of my coworkers is on my tushy for NOT fixing it and putting a slick hot rod paint job on.  I love my tank just the way it is.  It's dented, shows it's age, it's authentic to the bike I built, and doesn't leak.  It's perfect!  

Ooh, back to my previous topic... as it first seemed that only the hose was cracked and leaked, I changed only the hose.
But tonight I got quite some experience - standing by the road for the very first time. At first I thought that something really bad was going on, I heard two bangs and then stopped by the road, the bike not starting again. After a while and one helpful gentleman later, the bike started and I could drive about 500 metres and the same thing occurred (ok, without the bangs, but stopping just the same). After consulting with my well-experienced friends, I checked the gas level (there was some gas, although not much) and switched to reserve - and thanks to this, I am now home. And very grateful.

So I guess that yes, this is now the time to change the petcock! Or is it just a quirk of this bike that when the gas level goes rather low (but it's not out of gas), it doesn't get gas normally anymore?
Maybe I'm just so much newb that I ran out of gas like a normal newb does at least once
I do hope that all this was only gas-related because I was quite afraid of something more serious at the moment.

Two other lessons: always take your phone with you! And always stop and ask whether someone needs help. Thanks a lot to the guy who stopped.

Whitesavage, when you "run out of gas " the carb goes lean ,the bike misfires ,and the lean mix is pushed into the hot exhaust pipe and explodes (after fire) the backfire noise you heard.then if you put the bike on the sidestand to try restarting,you shifted fuel in the tank toward the petcock which allowed enough fuel to ride another 500meters before it quit again, then you found reserve. some times if you feel the motor missing you can turn the petcock quickly to reserve before it dies .So yes the "backfire" you heard is normal and could be somewhat louder than what you hear at idle when you turn the bike off .the banging noise or thumping you hear while shifting could be the fact that your shifting to a higher gear to early and opening the throttle to wide ,that will cause a knock -knock sound until the speed increases.try raising the speeds you shift at by 5-10 mph .