Mod-Chip and the PS2

[Jynx]

I have been looking at modchips for the ps2 and had some questions. Is it worth it to buy the mod chip and the gameshark 2 to be able to play backups? I have heard horror stories about unrepairable ps2's. This is a $300 machine and if Im going to spend another hundred I want to make sure it at least wont ruin my system. Who will install it? I have had no experience with a solder. Will an electronics store do it for me? I have heard that some games like EA Sports games are troublesome to boot up...
What about skipping? This was a big problem for the original playstation. I see they have ps2 laser calibration on psxcopyworld. What are your experiences with skipping? I orginaly tried to adjust my psx laser and had to send it in :-(
Finally what program to use/what disk media-are some games over 700mb?/what are the dangers of installing a modchip.
Good god I wrote a lot...Thanks go out in advance for any brave soul who replies.