Confused About Mod

[overweightninja]

So, if I want to, I can play Vanilla RTW or RTW BI without any trouble? Is there a special way I have to do it? Does EB have its own icon?

Yes, although the mod team officially say its not supported, providing you use a mod that doesnt change with any of the original Rome or BI files/folders you should be okay (and EB doesn't, btw I also use BI, IBFD and EB concurrently with no problems). As far as changing between games, yes you can change between them by using different shortcuts (I take it you mean shortcut when you say icon). This is done using "mod switch" in the command line (right click a shortcut, go properties).
Some examples:

C:\Games\RTW\RomeTW.exe -mod:eb - EB running under RTW
C:\Games\RTW\RomeTW-BI.exe -mod:eb - EB running under BI
C:\Games\RTW\RomeTW.exe - vanilla
C:\Games\RTW\RomeTW-BI.exe -mod:ibfd - IBFD running under BI

You could have all these shortcuts present and working at the same time if you wanted, and play the various combinations of games.
If you just let the installers make shortcuts for you and keep them all you probably won't even have to do any fiddling yourself.

You get better A.I. if you use the BI .exe, and you can find out how to do that by searching the forums. Either way, If you have EB installed, you should not have difficulty playing Vanilla BI. I actually have EB and a mod for BI known as IBFD both installed, and I could (if I wanted to) play the vanilla games even with the mods installed, because the mods are installed in their own folders.

"Better" AI is debatable, I would say "different". The main change is the AI makes increased use of Naval invasions, personally I use BI to play EB too but its up to you what you use, check the forums for some opinions.
And btw...heres a linky if you do decide to go with BI.
Hope that helps
Cheers!

EDIT And btw...."-showerr" is for error reporting, and I think "-nm" is also on by default, which disables into movies I think...