Greetinz Klystron...

Glad to have another fan around the forum. Yes, its a pity that when we were young...we tend not to know that its precious not to loose bits and pieces or even break them and start regretting now.

To answer some of your questions:
1. Depends on you really, there's no universal standard. You can even have muck shots of both modes or even most of the time, like me..MISB
2. If you wish to sell it, i'm sure there are many people who would love them. Checked it out on the identification guide and (hmmmm) skeletor was my first impression but well...would buy it if i'm gonna start collecting G1 Pretenders
3. No idea but have recently asked about repro labels shipping cost from TheDirtyDigger and he says that its rather "cheap"?
4. I'm sure Ebay has several MISB BW Injector... I happen to shared an auction with STL that comes with it
5. Yes I'm sure you can as long as it falls correctly into the Universal Counting Method

Have fun....