I have an Acecare and some cheap valve from Amazon. I have the bottle filled for a while now and it holds air just fine. I have a compressor too, so no need to buy a DOT approved bottle.
I would also like to add that shooting my air rifle improved my shooting in general. So while it's missing the recoil, you still get a lot of practice shooting.
I'm not sure if I understand what you are trying to say, but that is exactly why the handle is on the right side for right hand shooters and on the left for left hand shooters. You support the rifle with your non-dominant hand and push it into your shoulder (2 points of contact), the dominant...
I'm a total gun nut and bought 2 air rifles to be able to shoot at home and also to save on ammo. It tickles the itch, but it's not the same, so I probably sell an air rifle to finance a suppressor.