Ie the thin hollow box section from sill to tranny tunnel, usually around the front of the front seat. Made of about 1mm thick metal in an upside down U shape.

Not on all cars, but is on some.

Im presuming its a chassis strengthening part?

How bad is it, seriously, if i remove it? I know itd be fine if i remove it and re-weld it further forwards, but i cant weld and doubt i can get it done for 2weeks or so.

Is it ok to remove it? Just on one side. Just it makes fitting a floor mounted seat impossible with it there.

Its only my shitty S12, but its gonna get used hard and tho crash strength dont bother me, i dont want it to buckle like a banana with hard cornering.