We're building up a very large quantity of error_log* and stderr.log* files. Is there anything in LSWS that automagically cleans these up? I'm assuming there is no issue with just rm'ing the older ones?
Yes, you can safely remove any log file produced by LSWS.
LSWS has built-in log file clean up feature, to remove log file older than certain days, looks like it does not work that well, will investigate.