[Eru]

I've been crashing just about every night, hoping to set up a macro for non-gathering skills while I sleep, stealth being the current one.

I'm not sure if this is your situation, but for me, if UO loses connection for some reason, it will crash instead of showing the Connection Lost message. It may be that you lost connection at some point during the night and it crashed. This may actually explain a majority of crashes if this is a common problem with all installs.

I had constant crashes when macroing melee skills in merc. camp. while using razor.
The macro began with:
if hits <20
Walk left
Walk left
End if
and then the actual macro started comprising of autohealing, equiping gear.
The game crashed 2-3 seconds after I started the macro. This has not been the case before the restart.
When I deleted the first section of the macro (shown above) everything went well afterwards.

Razor seems to have problems with having the character walk. I had a similar problem. I wouldn't crash but if Razor *ever* took a single step for me, I could hardly move afterward without having massive lag-like symptoms. Like freezing for a moment after each step.