Sounds pretty harsh, but I think you should ban inactive members.--but don't ban the ones that contributed a lot to this guild[EG: Pyro, Razor etc].
You should ban people that hasn't been active for quite a long time and does not have a decent amount of posts. ALSO, after you've ban that player, send them a PM about why they are banned. You can also tell them that they are welcome to re-join the guild IF they promise to be active. That doesn't mean that they have to be online every single day--At least if not 3 times, but twice a week.. Here's a letter that I made to give you an idea:
Hello X,
You may have noticed that you've been banned. Please don't take this the wrong way for we are only trying to keep this guild as clean and as organized as possible. If you decide to become active and spare the time to post replies/topics on a guild, don't hesitate on re-joining AAFG. We would be honored. You can once again be a member by replying to this message. Thanks!
-AAFG Crew
Now, to invite NEW members, I think it would help if you make a thread on Gaia's Forum. It's not always effective, but it wouldn't hurt to try. Or just invite random players who likes anime XD!
..Let's try to reborn this guild. ^^