Cantilever not returning could be spring tension, corrosion, broken pieces/mis-placed spring, or the dreaded post bulge from over-tightening the mounting bolt.
Locking the rear wheel is not a sign of a well adjusted brake. Sure it gives the impression of lots of power but usually this is the result of a mis-matched lever to brake system. You want a brake you can hammer on and slow you down fast. Remember locking the wheel is not an effective way to stop though it is satisfying to be able to do it. A brake should have good modulation and you should be able to have a range of effective braking as you pull the lever in. If the throw is short and the brake locks quickly, that is a poorly adjusted brake.
Hangers are pure fashion. The original mafac/dia-compe ones work just fine. The shimano safety ones also work great when paired with the right cantilever and make adjustment straight forward.
Thanks for the info. I equate the level of power of a braking system with the ability to lock a wheel up in an emergency stopping situation. It is very clear on this bike comparing the front and rear braking that there is less power in the rear brake.
You guys have given me lots of things to look at to troubleshoot the rear brake.
Cheap, light and strong. Pick two.
1992 GT Edge; 1996 GT Zaskar; 2000 Rocky Mountain Hammer Race;
2012 Norco CCX monster cross custom build