hate to say this, but you can''t do anything about. nobody can. If he's the owner he can do whatever he wants. if he abuses it, just don't go on his server anymore.
that will be a new psu, since the avg vid card has at least a 6 pin conenctor. mine even has a 6pin and a 6+2pin. Then I would suggest replacing mobo and cpu at the same time as well. that way you only have to open your pc one time. (new mobo will also mean new RAM cuz you prob have ddr2 now)
trust me, you don't need the latest trend to run lfs at highest settings. you can even run it with decent fps on very, very old computers (not kidding)