Shock boots/mud guards

[DaveG28]

Checking over my car tonight and spotted I've ripped off a mud guard and also have damage on both rear shock boots...

So, how important are they? I assume mud guards just stop stuff clogging the dirveshafts etc so if I'm mainly racing nitro aren't too big of a deal?

Shock boots, well I know they protect the shock shaft, am I likely to damage anything hut the shaft by not running them on the back though? Don't mind knackering the shafts as I'll be upgrading them soon anyway, but only have limited spares till late July and don't want to risk other shock damage (eg to the bodies?)?

As all my spares are from the states would rather wait till I need a whole load to save on shipping!