Always BEFORE buying with a bore light. Check the muzzle crown and the breech for damage. Both can get boogered at the factory, distributor or retailer. If you find it after the sale, big hassle to get fixed. If used when bought, your problem. I also like to check the barrel for pitting and rust. If dirty, mostly I'll pass since the previous owner didn't even care to clean before selling.
This drives my buddies crazy who once read somewhere that a person shouldn't clean their guns unless it's absolutely necessary because it will affect accuracy. Personally I think that's total nonsense when it comes to a self defense firearm.
With the exception of a very small percentage of shooters/shooting-type, what you have described is far beyond what I would consider to be "overzealous" for every single one of the many firearms that I own.A rifle bore will copper foul after about 15 rnds and to maintain accuracy it needs to be brushed before firing another 15. The accuracy will drop off if you don't do this.
I never have. Never even crossed my mind.
However, I also don't look up the tailpipe of a new car before I start it, so that may have something to do with it.
I have been selling firearms for about 15 years. This statement is very true. Some manufactures recommend cleaning the firearm before firing.Storage grease is NOT a lubricant for operation.