advice please for right balance of tracks on mixdown

There is no such thing as the right balance of tracks in general. A trap many fall into is trying to make everything up front in the mix and huge. The important thing is to try to make the mix have a depth of field where certain things are up front and others more in the rear sounding. If you were just mixing a guy playing guitar and singing maybe

Yeah, just try and be conscious of the "everything louder than everything else" spiral. There's probably a small number of things (like 3 or fewer) that are most important in your song (this will vary by style and talent). Bring these to the front. The other stuff will play a supporting role from behind. To give a very rough example, for a typical hard rock tune you probably want to emphasize vocals, guitars and drums. Bass, keys, and auxiliary percussion (shakers etc) would be mixed back. For funk, you'd likely want to bring the bass up front and send the rhythm guitars back. Of course if you're in a hard rock band with the Most Amazingest Bass Player Ever(R)TM, then your mix will probably be more similar to the funk mix. Solos of course come up front. They basically take the place of the vocals. Listen to a mix you like in the same or similar style and try and make your mix similar.

and the other side of that argument: if an element is very quiet in a mix, consider completely cutting it out, unless it's contributing to the sense of space or texture. extra elements usually equal clutter.

thanks for the help, it makes sense and ill put it into practice.