Is it generally accepted that Clubs (Improvised Weapons) skill and speciality are applied to attack rolls made by firearms acting as melee weapons? Obviously they'd have melee hardening. What about using your firearms as melee weapons for the benefit of parry? Could you take Clubs (Parry) and have that apply to parry rolls?

From Arsenal improvised melee weapons:

I don't see why you couldn't parry with them either. I mean, there are no actual rules you can't parry with say, a Monofilament Whip using Exotic Weapon Proficiency: Monowhip. Using a gun would probably be easier than that

You can certainly parry with a gun, however, even with melee hardening, there should be a common-sense chance for damage to the weapon. I.e. parrying a club shouldn't cause any problems, but a crescent laser axe might...

Generally you parry an axe at the haft or by striking the side of the blade away from its target. Deflecting an axe blade is never a good choice.

Depends on the alternative.

Deflecting an oncoming axe blade with youe Ruger 100 sports rifle, and busting it: 900
Deflecting an oncoming axeblade with you skull and getting your greymatter stuffed into a new cyber skull: 15,000
Hoping your street doc doesnt add a few "options: Priceless.

Some things are priceless, for everything else, theres MasterVisa