Well, this is all water over the dam now,and I'm glad your job is done. All the advice given was excellent in my opinion.
re: soldering You have a teflon frying pan? No worries, mate. 95/5 solder melts at about 460 degrees, and if you use good technique the metal will only be slightly hotter than that. Teflon tape or paste will not be damaged.
That said, although a well done pipe thread connection will be fine, most prefer to solder directly to the valve. Soldering a body like this is somewhat more difficult that soldering a pipe into a fitting, so DIY valves are usually threaded. Despite varying recommendations from manufacturers, I always disassemble all parts of the valve just to be safe.
Your problem with pinholes: there are 2 key points in soldering: CLEAN & DRY. The necessary technique is then to get the parts up to temperature quickly and apply the solder just when the metal is hot enough to melt it. Overheating is probably the next most common failure ( after clean and dry!)
If you don't have the proper torch and tip, a prolonged application of heat the part in an attempt to get it hot leads to overheating.
I encourage you to try other projects in the future. And a little time spent practicing on scrap pieces will greatly improve your technique.
Good Luck!