We actually don't know the level of tech T'leth had at the time it went into the ocean; all the sonic tech and the like are necessary innovations due to its new, watery environment which don't tell us what T'leth was packing before then.
That said, T'leth and Cydonia are clearly related, and there's no doubt that T'leth did have rather advanced technology at the time of its crash; enough that it the aliens on Cydonia should be miles ahead of where they are. The only reasonable explanation is that there were several, near-terminal catastrophes between the time of T'leth's crash and Mars' assault on earth, with the Stellar Empire going through several rises and falls (or perhaps not even having been formed, with the various species which constitute it infighting during this time). On a timeline of tens of millions of years, it is doubtful whether even systemic social engineering could engender almost complete stasis for so long, even if for whatever reason a species was committed to such policy for so long.
Probably only solution is ask authors why this happened. For me only sensible exploitation is that they hit dead end and now only permuting existing technologies. Without real pan galactic civilization we can't say how it will behave. Right now Dioxine run this town, and he has last word about this.
And what you can do with it? Simply fork it. Create your own mode based on PirateZ and change it in way that you think made it better.
This is not that hard, you could simply start with your Chryssalid, copy paste it and start adding new stuff.
This is exactly that I did with Extended, instead of arguing with Warboy to trying change his goals I simply took burden on myself to create greater modding capacities in OpenXcom. And this was repeated by Meridian who start modifying my branch based on his own goals. With our collaboration we made piratez possible.
btw soon I plan add proper invisibility without using LOS hacks. You will be able made unit visible only up to 3 tiles away for solder. But with proper defection you could see him further.
There is no assault rifle _sufficiently_ better per the Pentagon's perspective than it that it justifies the expense of replacement. That said, there are most definitely better rifles (several American, German and Russian models come to mind).
That said, the Pentagon is most definitely on the look for a next gen assault rifle sufficiently cost and performance effective which would merit such replacement.
My point was that there will be not sufficiently better weapon than M16. Previously where was big replacements when tech switch from semi-auto to full-auto rifles. If they did not do it they would fall behind. Now they can postpone it indefinitely because they will never lose any battle only because they don't switch rifles.
In light of pending next gen body armour (nanotubes) I doubt it.
This is possible. If this armors could be mass producible then we will say goodbye to M1911 and M16 (and most of his current competitors).
Better armors probably will make renaissance of guns like this:
https://www.youtube.com/watch?v=C_dtC6ZOR3w even if bullet is stopped, released energy will crush bones and internal organs or cause brain concussion.