I will put up a test for all to see its functionality user-side, and I will expand on and retake those screenies above.
I think You are overcomplicating it, Jo.
This is not an installer. Its basically an unpacker, that support some scripting stuff. Like WinZip Selfextractor, but without the extra licensing cost. The scripting abilities are available in WinRar from start, at no extra cost or plugins requirements.
If one would take a look at the resulting script, by opening a packed file in WinRar, it would look something like this:
SAMPLE SCRIPT - DO NOT USE
The ONE BIG ISSUE this solve is the automated shortcut generation.
;The comment below contains SFX script commands
Title=This is a very nifty mod Window TITLE
This is a very nifty mod Window TEXT
License=This mod is subject to the following license Window TITLE
This mod is subject to the following license Window TEXT
Shortcut=D, "Bin\Release\Homeworld2.exe -mod mod.big", "", "Mod related mouseover shortcut text", "Name of shortcut"
User will be asked where to unpack files, and shortcut will be created in relation to that. And unpack will of course have to be to the \Homeworld 2\ root. Where ever it may be.
If a user altered the original Installation Path, it makes no difference. [ D:\Games\Sierra\HW2\ ] will work as well as the default.
User can still do wrong, but its harder. And it will not be because of the shortcut command syntax.
This requires no special software and really no skills whatsover to do right, and then I am thinking of the Mod Packager as well as on the user. It takes less than a minute to pack a 51 Mb .big file on a decent PC. And saves You 9 MB download, plus adds the shortcut functionality and works almost as an installer.