People who are really worried about repeated keystrokes can map everything to their $450 HOTAS flight stick.
The first, and probably the easiest step is to make sure that when similar functions have the same keys in different places. Such as 'f' and 'F' to follow. Most of this can probably be done through a keymapping file, which would be reflected in the in-game help, but then it would break compatibility with vanilla mappings in the wiki.
Not as easy, but already DFHacked, would be to keep the map cursor stable while hopping in and out of menus.
Complete information in the Legends mode exports, and let the third-party tools figure out the best way to present everything.
Keeping with the low-hanging fruit, I think the top-level menus (and maybe a handful of others) should be hot-keyed and keep the current selection. Have someone selected in loo(k) and jump to the squads menu where that guy is still selected the to thoughts-and-preferences then back to squads to take him out of the squad with four of his grudges.
At a higher level, I haven't read the abstracted interface thread, but in general that sounds like a good idea. De-coupling code usually makes sense (at least until you've come to a late round of optimization, if even then). Personally I'd like the option to keep the map and the menus in separate windows, but that's probably fairly specific to people who have dual-monitor setups. A distinct interface level would make that relatively straightforward in DFHack, even if it never made it into a init option for vanilla.
As for the map itself, TWBT and Armok Vision and so on would benefit greatly from an abstract interface, in that they could even become the primary interface (and I expect the authors would love to see Toady incorporate their work or ideas into the game itself).
The idea of little mannequins to show equipment or wounds won't work with a LOT of work to represent the arbitrarily complicated body plans in DF. May be work work doing for common body types, but I'd rather Toady spend his energy elsewhere. Again, the kind of thing that'd be easier with an abstracted interface layer.