I need to post some update on my situation. I'm no longer sure if the crashes I reported are connected to the mod. As I've said, I didn't have them with any other mod, but still, there was new development with my computer.
Yesterday my PC just crashed and never loaded Windows properly after that. I had to format my drive and make a fresh Win XP install. My configuration was likely very unstable, so crashes in any game or mod could well have been a result from this.
Also, I reached another important conclusion. I'm not sure how much it could affect crashes, but since I've done it now with my new Windows install, I suppose I've done it with the one that died.

I keep my RTW mod installs, so after the new Win install, I simply start the game and play. I've noticed that the Windows error message says 'illegal operation'. Might that be because a proper installation of RTW and BI hasn't been done? (Again, this doesn't seem to affect mods like RS and others.)
Maybe I'll try doing a proper install, reinstalling the mod and only
then playing some custom battles to see if the problem is in the units, in the mod itself. But if there are people with the same issues I suppose my crashes could be mod-related after all. Still, I felt obliged to report the problems with my system.