@Hikkaryu
1. For the stronger thing, in general people don't get stronger in this world. I also believe they also can't measure strength above S rank. Pretty much, it'll be hard for them to see that he got stronger (unless they detect aura or something). He can always just claim that he was always this strong (post second awakening).
2. As an S rank in the association (I assume the only one other than the boss), he can probably argue for a lot of freedom. Like ALOT. I mean seriously, he's mainly just there as a deterrent to keep everyone else (the other S rankers) from going out of line. That said, by the nature of this supposed job, yeah he's really only needed in emergencies. Guess that may be a problem then. But once again, emergencies that require an S rank to deal with are probably rare.
I suppose the route to take now is just to take occasional emergency job offers provided he's free...
The old dude seems like he'll be a recurring character who'll frequently request MC's help.