Trying to start from base FS2 to get there is hard because things are scattered all over the place!
At the very least you need the "fs_open" and the "mv_zpack" (which is also called the "MediaVPs" just to confuse everyone more), and they have to be matching versions or weird crap happens.
(So if you get the v3.6.7 fs_open, make sure you get the v3.6.7 mv_zpack, and if you get fs_open_368 get the v3.6.8 mv_zpack!)
I'd post URLs but they're in the Wiki (And I forgot all of them anyway
)
In all honesty, downloading Shivan's BitTorrent is the EASIEST way to get started; It's slightly out of date since they keep updating so quickly but it is a good place to start.
But, if you don't mind the 1.7GB download, I'd go for that.
I've been uploading at a throttled 8kB/s for smeg-knows how long with a total of 10GB uploaded and it's still hammering out solidly at 8kB/s as I type!
(See, if they did 8MB DSL up AND down instead of some stupid crap like 8MB Up/512kB down I would bother upgrading my line!)
The launcher problems sound like you have weird options set; The Wiki has a (sketchy) guide to all the launcher options; Use that to configure yours.
If you're not sure about something, best to leave it off or ask here.
I'd post my launcher options as a guide but I don't have access to my games machine right now...