1. Unfortunately, with how this game is made, not possible.
2. It's just another game mechanic, so too little for DLC imo. If ever, I suspect it added in an update or something. But I highly doubt it.
3. I personally have mixed feeling about this. Doesn't really add much to the game. Point 1. is just renamed electrical grid, point 2 just adds phones on top of already existing TV, radio and computers. Point 3. - secret police is never an issue in this game, they are useless in most cases anyway, so don't think it will add much, but more research is good imo. Point 4. basically just makes what electronics already make in the game so nothing new.

Now that a early DLC is out, maybe a late/future DLC is next. I'd see telecoms, with internet satisfying the population but also spread dissent if things are bad somewhere in the republic. Maybe it could be part of a Glasnost, chose transparency to get people happier, but risk everyone losing loyalty if something really bad happens somewhere.

Also, small scale private enterprise could be allowed under perestroika, they would buy from a supplier of their choice autonomously, getting you revenue, but people buying there would cost you something.

It could also be nice to have offices that would design new vehicules (either to copy designs rather than buying them or as a way to get improved vehicules or factories designs).

Also, perhaps a military DLC could be good, with a system of orders/requests from the Warsaw Pact in exchange for favors, lower prices or just staying alive.