Theory of orings says you should replace them if they are 6 years old, but in reality they are probably fine unless they are worn or dirty.
It is probably just coincidence that is started leaking after you changed the air lines. The only other thing that may have directly contributed, is if you used teflon tape and a tiny strand or two got into the valve, or if some of the old sealer from around the fittings got into the valve when it was dislodged when you changed the fittings. A good cleaning of the valve will do it good and allow you to check the condition of the orings.
You have an X-valve so the regulator piston assembly is the high pressure version. The piston assemblies don't usually go bad, so I doubt that is a problem. A leak out the back is probably just a piece of dirt in the regulator seat oring or a piece of dirt in the oring surrounding the regulator piston assembly. A good check is to reduce the velocity setting. If your piston assembly is worn out, the leak out the back will go away. If it doesn't go away, then the leak is due to a bad or dirty oring.
Holding the trigger should cause any leak out the front to stop. However, if you have too many shims installed in your powertube it could persist as a slight hiss for quite a while.
You should probably tune your level 10, since your mag has sat for a while. The orings might have swelled or changed dimensions slightly, which would affect its operation.
Except for the Automag in front, its usually the man behind the equipment that counts.