1 the text appears to small at 1080p and there is no apparent way to zoom it up
Are you using "standard view" on your TV (with windows etc) in order to view and manage your collection? For use on a HTPC with a TV, Theater View is recommended which is a 10-foot interface. I think the normal view interface is more designed for a monitor.
2 Also I would like to add say several CD albums into 1 folder Name the folder and add an image to the root of that folder
Then import that folder into MC18, and when I click on the folder image show the albums I have in the folder
each CD being in its own folder with it's appropriate image.This is so I can group several CD of the same artist
This can be done in XBMC / although not in MC18 /or not that I can see
I think this is the "boxed set" conundrum, wher you need one level more than the usual Artist/Album structure. However, if you want to group multiple CDs by Artist then I think this should already work. Put the artist name into Album Artist and your views should then drill down from Artist into multiple albums automatically. What might not work is to have one overall image for the artist, but I remember something about functionality being introduced for Artist Images, but I can't remember exactly what this did. Probably a search on the forum should uncover something!
3 Also I have several compilation CD albums and when I try to import them into MC 18 / they import as separate individual tracks/artists
Make sure that the albums are tagged correctly, i.e. that all tracks from the same CD have the same Album name and the same Album Artist (which you can call Various Artists or whatever).
Note that MC does not care about your folder structure on disk, it only arranges media by the metadata tags. So if your media are not displaying correctly as you would like them to, you need to check your tags carefully.