Hm, not sure whether you mean these differences with the Zerg are considered limitations or improvements compared to the standard 'horde of alien locusts" trope.
Well, you have to consider that the Zerg were conceivably shattered and divided by the end of Sc1, so there'd be no need to team up. Also, the Dominion could have also easily filled in the role as main antagonist (that the UED ultimately did) after Sc1, if there really had to be an overarching antagonist for a sequel/expansion. Problem with that was that there's this impression that the Terrans were crippled by the end of Sc1 as well (more than 2/3 of their core worlds were laid to waste), so in a way, the UED was kind of a necessary conceit/plot device to put the Terrans in general back on the table of relevancy.
Indeed. Teleporters in themselves make for very effective weapons, too, when you think about it (no need to put them back together again, right?).
The sci-fi (which is admittedly light considering other sci-fi universes) in the Dune universe is interesting in that there's distinct workarounds/explanations for why certain things are the way they are. Lack of firearms due to the effectiveness of shields (hence slow dart guns and melee weapon skill being important) and that the only method around them is assured mutual destruction (lasers striking shields create atomic explosions). No space battles are present because the only means of space travel/transport is determined by the Spacing Guild. And so on. (Man, I'm cautiously optimistic about the upcoming film...).
Fair enough. I think my point still stands though that the Terrans need to beefier/stronger/hardier from the get-go in order for any sort of "ongoing" thing to take place. It's interesting to note that you do intend to end it with the Terrans ultimate demise, since that would suggest a greater need to make the Terrans stronger up-front initially/ shed the weak and isolated premise they were originally conceived as.
I love Farscape! This was also on my mind when I mentioned the Overmind's capability of generating wormholes earlier.
Well, one can still dream, right? That's were all the best fluff is, afterall.