WMA has a lossless format. There are others, but I wouldn't try to list them - I use WMA. This approach definitely gives you bit-for-bit support, and loading them all up and running them from computer definitely gives you the flexibility you describe. You might get an audiophile demerit, but it certainly is the right way to interact with a music collection for me.
WMA isn't supported by iTunes. Again, there are others that are, but not WMA.
WMA isn't supported by iTunes. Again, there are others that are, but not WMA.