1)
Can mining rigs be used for something else, (if/when it is payed off, becomes cost ineffective) ?
I intend to buy 1 motherboard that can hold 2 or 4 graphic cards,
Could I run chess software on those graphic cards, to have a home chess "supercomputer" ?
I don't understand this, what OS is installed on mining rigs, linux, or something custom made for mining only?
I was thinking something like linux - wine - fritz software configuration on it...
2)
What should i do with bitcoin client on my computer ?
I have bought some btc, waiting for the "this time next year" scenario
I have stored several copies of encripted wallet.dat here and there...
I don't intend to spend them soon.
Should I just uninstall the bitcoin, so that some virus or worm or trojan could not find wallet on my pc ?
later, I just download and install bitcoin, copy paste wallet.dat in it ?
Is that how it should be done?
I don't want to screw something up...
1. Yes, you could probably run something like F@H.
1a) no idea
1b) You can use Windows, Mac or Unix, doesn't matter.
1c) ^
2. At the moment I recommend waiting, this time last week they sold for about $6.50, now it's fluctuating around $8-9
Should I just uninstall the bitcoin, so that some virus or worm or trojan could not find wallet on my pc ?
That won't make a difference, if you want them to be safe without encrypting, move them to a different directory, and rename.
later, I just download and install bitcoin, copy paste wallet.dat in it ?
Yep