well then I would have to say that your not really writing all the songs, your just coming up with a guitar riff and the you take it to the band and you all write it together. I thought that was how most bands write music. If you had written every part and all they were doing is reading it of a sheet then you would be writing all your bands songs. If your just writing guitar parts and not the other instruments then you shouldn't expect your drummer to come in with a guitar riff to try out. He wrote his parts it sounds like.

I would just encourage your drummer to come up with some grooves or something that sound good that you guys can jam on and your bassist to practice and to right cool bass parts. Unless they just really aren't any good, but you should still encourage everyone to contribute their own ideas, you may find a really great band dynamic comes out of it.

In my opinion you shouldn't always write songs from the guitarist perspective only, but thats just me, Im sure a lot of bands do and they sound great. I guess my point is that, in my opinion you didn't really write all your bands songs.

Copyright it as the bands, and when you guys break up and get in legal battles over who wrote the songs then maybe you'd have a case for keeping the copyrights but if that doesn't happen it doesn't seem worth it to alienate the rest of the band, dig?