What's the name of those little posts that you find on the streets that firefighters use to get water?
i always preferred sterling solder and nokorode flux, c-flux is ok, make sure you clean the pipe and fittings
My wife uses a hot glue gun and it came with the sticks we got it at hobby lobby for around 10 dollars i use it a lot on other things it was worth it
Use Alpha metals solid core lead free solder and Nokorode soldering paste. (avail at Ace Hardware)You may have better results using Mapp gas instead of propane as it is hotter,but be careful not to melt any valve seats. And be sure you clean the surfaces with a fine emery before sweating.50/50 is no longer acceptable for plumbing.
I have to assume that you are using hard copper and not soft copper. You might try heating it with a propane torch to help soften it up a bit. Again I have to assume that the tubing has nothing in it. They do make what is known as a bending spring which slide over the tubing and helps support the walls to keep from kinking. You might also try the bending tool that electricians use to bend conduit.. If the bend does not have to be to sharp should not be to much trouble. If you are using soft copper, should be no problem as it comes in a coil, and it might be better to use the soft copper if this is a new water line or an add on.
If you can use end-feed fittings (plain solder type) on all new copper work, and stick to compression fittings (spanner and olives) on older pipework - you won't have problems. Use a little jointing paste on the pipe - when fitting olive - and tighten up. End-feed copper fittings are cheapest for new runs, and neater, but if you are working wet, or older pipes - clean up first, cut, then fit a compression service valve as the first thing you do. After that, you can take your time and make the rest as neat as you like.
