The answer is a big NO on that one. The fps you see is the fps you get. You *might* be able to squeeze 1 or 2 more fps out, but is that really going to make a big difference? Not really.
As for the "lack" of games on the Gamecube, I don't know what you're talking about. It's got tons of great games. Starfox: Assault; Metroid Prime (1&2); Tales of Symphonia (which is also on the PS2 in Japan); Beyond Good and Evil (which is on all 3 systems); Zelda9: The Wind Waker; Phantasy Star Online 1&2 (which is also on the Dreamcast and Xbox); Skies of Arcadia (also on Dreamcast); F-Zero GX; Super Smash Brothers: Melee; Mario Kart: Double Dash; and ect. There's tons of great games. Certainly enough to make buying a Gamecube worth the expense. But no, chances are slim that many more games will be made of the Gamecube. Though, Zelda12: Twilight Princess is coming out this fall for the Gamecube, so there is that as well. On the other hand, you might be better off waiting for the Revolution (renamed "Wii") to come out. It's backwards compatible to all of Nintendo's previous systems (via the virtual console and downloads), including the Gamecube (via the actual disks themselves). And, chances are pretty good that it's only going to be about twice the price of the Gamecube (In the U.S.A., the GC is $100.00). Look up the features of the Revolution. So far as I know, everyone that has actually used the controller has only had positive comments to say about it. Not a single person has said that they didn't like it (there were nuetral comments, but no bad ones). There's even some people who trash-talked the system (basically said it was garbage), and once they got their hands on it, they changed their minds. I don't know about you, but for me, that says something about the system. Even those who hate it like it, once they tried it out (or, at least didn't hate it anymore). So, it might be wise to simply wait for that.
Of course, when it comes out, chances are pretty good that you'll be able to find a Gamecube for dirt cheap. People will almost certainly be selling them off, since the new system can play their old GC games. Hopefully I provided some useful and helpful information to you. Also, I'm sorry if I provided to much information... Sorry for the long read. Mouser X over and out.