1 sounds like a MOD could do that. Research a tech that opens all choice techs so they can be researched.
Eh, maybe. Just thinking about how to do it though makes me break out in hives.
The main problem, as far as I know, is how the base game treats any tech that is tagged as a Specialization. As it currently stands, again as far as I know, a tech is a specialization or it isn't. If it is a specialization, it is subjected to certain rules that I don't think are modifiable by us lowly peons.
I'm not entierly sure what triggers one can put on a tech to make it researchable outside of techs themselves. If it is possible to play with that, it might be possible to set up some ridiculous branches that might do this sort of thing.
I suppose looking at Ave's DeSpecify might help a little, but there were a some issues with it in regards to trading techs, IIRC. I never really did come close to understanding exactly what he did there, which is why I went in an entierly different direction for my Generalized Tech mod.