GLS Audio 100 feet Mic Cable Patch Cords - XLR Male to XLR Female Black Microphone Cables - 100 feet Balanced Mike Snake Cord - Single

Q: I need to make up 8 short cables, mixed male/female. Don't want to buy a big bulk roll. Can I cut this cable up and solder my own connectors?

Certainly! Cable is cable, and this is fairly high quality cable. Lazy as I am, I have in the past simply ordered 6', 10', 12', and 15' cable lengths.

Q: Will this cord work on a fantom power proximity mic?

I am not sure about the mic but if it works 15 sub perfectly then it should work the mic even better

Q: What gauge wire does this cable have? 24 awg 16 awg?

Sorry, don't know. Ask Amazon if their specs are incomplete.

Q: Can/Should I connect 2 of these together to get 200ft or is that just too long?

Can you, absolutely. Should you, that's a better question. In theory, as long as the cable is properly balanced you should be able to run it well over 200ft, I'd say 200 to 300 yards shouldn't cause a problem. The only problem I could see is you are not running a continuous cable the whole way, it has to go through a connector, though 1 extra connection probably won't cause a noticeable degradation.