I've had Mezzmo for several months, and got it set up 90% very quickly, but I find it impossible to set up my TV shows as I want them. Can you help?

My sample scenario:

Say I have four Blackadder episodes from two series and four Monty Python episodes from two series
I also have four Canal Shows from two series and four Railway Shows from two series.

I want to control my metadata totally from nfo files. I know how to set these up, but Mezzmo seems to have hard-coded logic which overrides some entries, and the mapping from the nfo file into the Mezzmo library isn't clear to me.

I would like to see a tree like this:

>TV Shows
>Comedy
>Blackadder
>Series 1
E1 Title of S1E1
E2 Title of S1E2
>Series 2
E1 Title of S2E1
E2 Title of S2E2
>Monty Python
>Series 1
E1 Title of S1E1
E2 Title of S1E2
>Series 2
E1 Title of S2E1
E2 Title of S2E2
>Transport
>Canals
>Series 1
E1 Title of S1E1
E2 Title of S1E2
>Series 2
E1 Title of S2E1
E2 Title of S2E2
>Railways
>Series 1
E1 Title of S1E1
E2 Title of S1E2
>Series 2
E1 Title of S2E1
E2 Title of S2E2

My problems are:
1. I need a fixed value in every one of the 16 episodes - say 'TV Shows'. Must it be TV Shows? or TV Series (there seems to be hard-coding here)? And which nfo field should be used? Where should this map to in the library?
I have failed to get all of my TV shows under the TV Shows branch. I was working on the basis that TV Show should be a Category, but some series which have this don't turn up in the branch.
2. Comedy and Transport need to be in a field which is in the Keyword Hierarchy of the Active Playlist. Which field should I use in the nfo file, and where would it map to in the library?
3. The program names (eg. Blackadder) need to be in a different field which is in the Keyword Hierarchy of the Active Playlist. Again, which field in the nfo file, and where would it map to in the library?
4. So which three fields would I need in the Keyword Hierarchy?
5. I'm OK with the display of the titles.

I'd be most grateful for the answers.

And ... why can't I search for 'TV' in this forum???