I spoke with the maker of minimal_mod and he provided pointers on how to do what you are requesting... I am busy for the time being but might have some free time this weekend to implement his suggestion.
I modified the theme to support SenderColors if you select the variant but to do #2 would break the layout of the theme... best I could do is append the sent time on the same line as the text rather than next to the username. Not sure if I like that.
# by sammargh on 01/14/11 at 16:33:31