I think you'll save yourself a lot of trouble if you just go out now and buy a db9-to-db9 cable and a null-modem adapter.
Connect it to a PC with a real serial port. Try with and without the null-modem adapter. If it still doesn't work, reset the switch.
If that still doesn't work, I'd...
I guess that by "won't run shit" you mean "won't run games."
That G3 needs a memory upgrade, but after that it would be perfectly acceptable for a general-use laptop. Sure, it won't run Leopard, but you don't *need* Leopard.
However, look around. You can get an 800MHz white iBook for...
From perusing the docs, it appears you need a null-modem cable to connect a PC to the console on a Powerconnect 3024.
VT100 emulation is less important than they make it out to be, and almost every terminal emulator supports VT100.