I think I can do what you want, both with the coloums and alternating colours, but I'm going to need to see some of your templates first.
I'm going to need part of your FORUMHOME template, everything from
<!-- latest threads start --> to
<!-- latest threads end -->, and the whole of your forumhome_latestthreadbit template.
It would also be handy if you could give me the content of your 'Latest Threads on Forum Home' plugin.
If you can paste that info here, I'll see what I can do for you