my 10/22 has over 130,000 rounds fired and id hate to guess the number of dry fires. probably in the thousands. ive never replaced the firing pin.
LRHO - i removed mine entirely years ago. i tired of tinkering with it trying to make it work right. the LRHO kits are finicky to say teh least, besides requiring special mags. i never put the factory bolt lock back in cause i never used it anyway.