I guess influence might be more of a bottleneck if you play with a less densely populated galaxy so you’re constantly building outposts, rather than the early scramble to stake territory and take chokepoints before the borders solidify
That might be actually. I play with empire populations maxxed out so I don't actually need to expand for long before running into other empires.
Influence does limit your expansion, it represents political and diplomatic capital. I'm getting about +3 in my Boatmurdered 2200 playthrough. There used to be techs increasing it but those have been switched over to providing unity, which is like a different kind of civics-building resource. It's somewhat more desirable than having to spend influence to colonize planets though.
Influence will be a problem on big galaxies, and I play on 1000-star ones. The trouble is influence does not scale with galaxy size, so a "big" empire in a small galaxy will have an easier time filling up space than a "big" empire in a full size one. The further you expand, the more systems you have to claim (with outposts) to expand your radius of influence (systems to claim squares with distance). Any conventional empire will slow down expansion of its bubble because of this, either spending influence on outposts or claims.
I haven't gotten a hold of how the AI scales in terms of results (not on the scaling difficulty, talking Ensign-Grand Admiral ones) so I'm playing it safe (maxed out empires, habitable planets, primitives, etc.), I might have to edit the difficulty upwards though (as a rule of thumb, AI are almost always given a resource and power bonus to scale difficulty but I do not know if this expands to influence). I'd played a game back in 1.8 and while the colony system was hell (influence for colonization, maaaan) the influence blobbing was easier... had covered a decent part of the galaxy by 2300-2320 (with hyperdrives, other empires had different FTL methods though). If you had democratic government, you also got influence from fulfilling mandates (lots of it, every ten years or less), but that's been changed to unity. I did manage to get a lot of influence uplifting pre-sentients though and that's how I got by - 500 influence per uplift gave enough to colonize about five planets. If it still gives influence in 2.0 that would be great, allow about 6-60+ systems to be outposted/uplift depending on what the cost reduction you have is.
There was a recent dev diary with some interesting stuff. I am not going to copy the whole thing over, but highlights are:
-Space Creature research is being remade. Now you can either choose to hunt them, getting a damage buff against them, or study them, resulting in stuff like the current system, or, in a few cases, try to tame/co-exist with them, resulting in components and such. Pet space amoebas when?
-All strategic resources will be visible from the start, but most will require tech to be exploited. This is nice.
-A mid-game tech has been added which allows science ships to use... the old warp drives. Yup. You need to have revealed the target system through sensor range at some point, and it won't work with special stuff like the upcoming L-Cluster.
Unlike warp drives, there isn't a range limit and you can "go anywhere" as long as it is to a system there's some intel on (have visited before). If you have intel on a spot on the other side of a 1000 star galaxy, you can go there in one jump without interception or worrying about space borders. It's also only for science ships.
Ok, so I picked the psionic weapon as my choice of planetkiller... amd NOW I've found that it's not a psychic dominator at all, it just makes people more spiritual. Can I salvage this somehow and get some other PK weapon?
You can apparently refit the planetkiller, if you have the tech for it. You might have to wait for it to show up in a research tree though.