Current crop of Rugers are still keepers. Some have reported jamming problems, but that is usually fixed with an ammo change until the gun is properly broken in; low velocity ammo in a new gun is a frustrating combo. Other problems have been bent mag lips. My first Mk II jammed with high and low velocity ammo when new, but ate everything fine after a couple bricks of high velocity ammo. My second one (only a couple bricks old) is still jamming occasionally with the low velocity match ammo, but never jammed on anything else. New one puts 10 bullets through one very small hole from a rest, its accuracy is better than my very accurate 22 rifle at 25 yards. Haven't taken it to the outdoor range yet, but I will as soon as I go there on a windless day.
I swapped my trigger because I like to tinker. Yes, the new trigger is very nice, but the factory one was fine as well, feeling a lot like some of my 1911s.
You will only damage your MkII or 22/45 by dryfiring if you don't put it together properly. There is a firing pin stop in the bolt that keeps the pin off the feed ramp; forget to put that in and the pin will dent the ramp. Remember, you have to dry fire the gun to field strip.
Cleaning: I'm with you. Q-tip in the chamber to knock off the crud, drop of oil on the recoil rod, another on the bolt, rack, dryfire, wipe 'er down and put away. I field strip and clean every couple bricks. (no, I don't treat my other guns this way, just the MkII, it runs better this way).
Final comment: have you looked at some of the 1911 22 conversions? 22/45 is close in feel (grip and controls), but there's nothing like using the same manual of arms to stay sharp. Marvel makes an outstanding conversion that is next on my list (in CA we can only transfer one handgun/month and I'm booked through Feb). http://www.marvelprecision.com/ Ciener also makes one for less money, but comments on some of the boards have run to the negative side (Ciener is the one Kimber sells).