1) selecting different tools while the game is paused
I assume you mean with the mouse, because it is possible already with F3-F10.
It is possible to implement this.
2) unpausing by clicking the screen or assigning a task
3) holding left or right to select a lemming walking in the indicated direction
Yeah this could affect gameplay seriously, but these are good ideas for future extensions.
When the dos-clones are ready the plan is to create a seperate extension of the originals, a bit like Cheapo (although I never played it, my monitor does not like it).
And when my programming skills and time allow I would like to build a style+animation editor too.
So maybe the ideas have to be seperated
1) Extend dos-clones, without violating (a good example is replay)
2) Ideas for new lemmingthings (like higher levels, with vertical scrolling), as long it does not become WarCraft
The Cheapo bridges I like (with 12 colors).