How tight of a hover should I be able to do with my blade cp? I've been through about 6 charges with the stock pack so far. I started out just moving it around on the ground in my basement. I was having a hard time getting the tail to hold still and not spin, I worked with the trim a bit and that seemed to help but it still works around some.

I'm still having fun and so far the only thing I've messed up was a set of blades!

if you can hover a cp heli in the tight confines of a house, then that's already very good. now practice all orientations side in and nose in (maybe you should do this outside).

a good gyro like the gy401/240, will hold the tail.

i can fly my x400 from liftoff to landing the whole pack without giving a single rudder input, and it wont move.

Well I can't really hover yet. The problem is every time I try to correct the heli the tail will move around. I have to keep putting rudder inputs into it to bring the tail around to orient myself.

You may want to adjust the proportional. Check the manual on how to do that. The tail should not spin around if your not even off the ground.

One thing to note on the BCP, once you get off the ground in a hover the tail trim will probably change so once you get good at hovering trim the tail to center while hovering. Also, on mine, the tail will stay steady at hover but as I give more pitch it swings to the left so you may have to fly the tail quite often.

Ok so it is normal to have to give some tail input while flying even though I'm not trying to turn? I have to "maintain" a straight tail then?

Absolutely. If your in a steady hover without going up or down, the tail should stay in one place. If it doesn't, you need to trim it until it does.
Once you start going up and down, you will definately have to supply input to keep the tail where you want it.