There are plenty of FC/LS in the Hall that aren't active but there are tons that are. You've posted in several threads in the LS hall, have you gone through their recruitment processes? I know for a fact at least one of the threads you posted in is active. Don't just look for warm bodies though, pick a theme and group that fits your playstyle and your characters.
Good ways to judge activity is how recently the thread in the LS Hall was posted in as well as checking out the FC's website. Another way is to look the FC up in game and keep an eye on how many members they have online at any given time. This isn't fool proof though. I've been in guilds with 30 members online at once who rarely talk and never actually RP and in guilds with only five or six that are super chatty with active RP.
Good ways to judge activity is how recently the thread in the LS Hall was posted in as well as checking out the FC's website. Another way is to look the FC up in game and keep an eye on how many members they have online at any given time. This isn't fool proof though. I've been in guilds with 30 members online at once who rarely talk and never actually RP and in guilds with only five or six that are super chatty with active RP.