(1) BI is either not patched or has only one patch in the Gold Edition. (mine anyway) Go to options and it will give you the version # in the upper right corner. Should be 1.6.

(2) You can't just change the descr_strat for BI. Why? Because some of the factions you are trying to play are emergent (such as Romano-British or Slavs). Why don't the others work? I dunno. But when I did the same thing I had the same problem. I could only play as one or two civs.

You have to get the unlock all BI factions mod. Lotsa fun. Here is link: https://forums.totalwar.org/vb/showthread.php?t=57734

I liked playing the E. Roman Empire rebels, myself. :)

It'll give you instructions. This one doesn't seem like the mod I used though. ??? It looks like you have to start as one of the playable factions and it'll give you the option of taking an emergent faction when it arrives.

I found one somewhere that lets you start as the eleutheroi (rebels pardon me) and then it has you select a specific city for which faction you wanna play. I'll post the link if I find it. Or I could burn my cd of mods and send it to you in the mail! hmmm...

Good luck w/ BI! Enjoy!