Lua is fast and easy. The problem is the very annoying manual, but there is a very active mailing list with lots of gurus which helps when you need.
About integration, take a look at my very simple test apps.
There is a nice small AI there in the /userdata directory (each entity will try to kill another or defend itself using the adequate method according to its class).
I'll check out your stuff in the future. I'm not exactly at the point where I can embed the language yet. I need to work on some other stuff
BTW, why did you go with Lua? Is it because of the speed and small size?
If you want some performance figures, check this out:
It is only theoretical tests but it gives a rough idea of the performance.