You are in UK. Of course, they won't sell you a knife set. They are designated as deadly weapon in UK. I hope they will let you keep your butter knives :) With NHS, British teeth don't look like much of a cutting tool. J/K!!!
It all depends on the pipe and the person smoking it. I always clean as soon as I'm done smoking. And I do take my pipes apart middle of smoking also. Some times, the tenon will get stuck. I think that's fashionable like JRRT.
There are ways to fix badly packed bowl without dumping it. It all depends on where the problem is. However, first thing I do is put pipe cleaner all the way to bottom of the chamber and open up the air way.
Never really had "comfort food tobacco". Other than codger blends, I haven't smoked same tin twice. There are so many blends out there. Capt. Black Royal could be it, or Carter Hall. They two blends I smoke if I'm out of an idea.
After using tobacco for 40+ years, nothing seems to bother me. Well, fresh out of tin red Va gives me nausea. But, after few weeks in a jar, they are great.
Army mounts are different from most shown on your pictures. The army mounts have tapered stem that can be fitted into mortise by friction. There won't be separate tenon like typical pipes.