Gigabyte Mobo with Keyboard PS2 port failure

Strange little problem I got here. I run my selfbuilt system with a Gigabyte
GA-7DX Motherboard, Athlon 1.33GHz, 512MB of 2100 DDR-SDRam and Win2000.

A few months ago my Keyboard stopped working, I think first intermittently
with beeping noises from the systems speaker. I soon found out that the PS2
connector was at fault and I plugged my Keyboard into my USB port and
everything works fine now.

The problem with this solution is though that I have got no Keyboard
available when Windows is not running, i.e. I cannot select to get into BIOS
and I do not want to know what's going to happen once Windows spits the
dummy (which will happen sooner rather than later the way I am going). Don't
get me wrong I fairly know what I am doing but I still expect a full
reformat and system reinstall every 12-18 months or so.

My 3 questions now a

1) Is there ANY way to get the USB Keyboard (and the USB port therefore)
working without Windows, i.e. to get to BIOS etc... There surely must be
computers around that only use USB Keyboards or do you still absolutely need
a PS2 port for the keyboard???

2) Since my PS2 port on the motherboard is dead, has anyone ever had a
similar problem? Is that a known thing (happened to me the first time in 5
years) and does anyone know a trick or hint for my problem. Obviously
replacing the motherboard will do the trick (which I will have a question
about anyway in question 3), but is it possible to just replace the
connector or could there be some sort of controller at fault?

3) If all else fails I will replace my motherboard before Windows spits the
dummy and I cannot access my BIOS or reinstall Windows via boot CD.

That brings me to an additional question, since I then plan to upgrade my
motherboard, is it possible to upgrade to a latest Athlon Mobo and still use
my old 1.33GHz CPU and my 2100 DDR-Ram (meaning are those new motherboards
downwards compatible with the older Athlon CPU's and RAM) or do I then need
to buy new RAM and a new CPU as well????

Thanks for any help!

Hans