"the limitation that I cannot press a lot of keys at once"

What limitation?

Ctrl+Alt+Del should tell you immediataly that the standard matrix layout has no problem with pressing a lot of keys at once!!!

The PC keyboard & mouse interface (PS/2 and AT) come up with monotonous regularity on this site - just use the 'Search' button and see what a wealth of stuff already exists right under your very nose!
(including loads of links to other sites all over the internet).