Ahh, ok then, and I thought this actually WAS trying to make original Liero better. Well, guess I have to still stick with the "real" Liero then, while I rewrite this one to suit my needs, or even write a totally new version using your and other codes as examples. Never know, what new ideas time will bring.
In the very beginning that was the idea indeed but you are almost 10 years late as the development has totally drifted away from Liero for DOS 
It was? I thought LX has different physics by purpose. Gusanos was actually more a try to be close to the original (but still much extended and much more modable). But it was less popular for other reasons. And of course it depends on the mod. The physics are after all more original Liero like. And mods like Promode share many original weapons in a somewhat more modern and typical Promode (as in other games) way. And then there is also OpenLiero which is a quite exact clone of the original.
I've noticed that so many programmers deny this fact and now My Documents is being targeted as a storage for crap - useless files, logs, configs and critical installation data, that shouldn't even be in there. I had to abandon My Documents, since that wasn't "My" anymore and create a separate folder for my real belongings.
Oh, how I miss the good old days, when all data was kept only inside program's own installation folder... no registry corruption, no dependency on %AppData% or %HomePath%... 
User-dependent app data (such as configs) should never go into the global application directory. It depends on the user. (I'm not sure if I really should try to explain these basics here. That is just how it is supposed to work.) It should actually go to %AppData% (the name says it already) instead of %MyDocs%. We decided earlier for %MyDocs% because it can be important for a user to find that directory (e.g. to edit the config or to place downloaded levels/mods in it). Also, at that time, I found that this was common for other games. Maybe %AppData% would be a better decision now and I was already thinking about changing that (however, that can again cause confusion now, etc.).
Btw., if you really don't like this, this is all configureable. Move the OpenLieroX directory from My Documents to where you want it. Maybe, if you want, just merge it with the OpenLieroX application directory and make that directory writeable for your main user. Then edit the cfg/options.cfg. Under FileHandling, the searchpaths are defined. The first search path is also the path where OLX will write to. So just put your favorited directory there. E.g., maybe you just want to put ${BIN} (which is the directory of the exe) there. This would behave like a portable app then (a portable app is mostly what you are missing from "the good old days" - the program and all its configs merged together).
Another note: The application directory of OLX was always self-contained. There aren't any critical installation data anywhere else. You can just remove OpenLieroX from My Documents and OLX will run normally (just with a completely cleaned/reset profile).
Also read the post from Kurko. And the linked VFS wiki page for more information about how the search path system / the
VFS works and in what way you can configure it.
Btw, if you're going to make another Liero clone, it would be nice to have online multiplay in OpenLiero (now Liero 1.35). It's open source so you can use it as a code base. I think there was a hack for OpenLieroX ("Liero Orthodox" or something) that allowed playing original Liero/Openliero online but it didn't work very well.
http://liero.be/
The source can be found here:
http://code.google.com/p/liero/It's quite nice to read. And the physics are really simple. The earlier hack in OLX to include OpenLiero was really ugly and was removed. But I thought of adapting the physics somehow in another way as a simple OLX mod, i.e. the original DOS Liero directory would act as an OLX mod.
If you want to extend OpenLiero to add network support or so, you should speak with Gliptic (Erik Lindroos). He is the main developer behind the project and he can help you a lot. (Gliptic is also one of the main developers of Gusanos, btw.) He is also a quite nice/friendly guy. He often hangs out on #liero @quakenet (as well as other main people of the Liero community, e.g. Joosa Riekkinen, etc.).
If you want to extend OLX to include the OpenLiero physics (or like I said: as a possible mod engine), I would be very interested in that. I can introduce you to the OLX code if you want.