gonna put more context into it.
1. the diplomacy system is incredible, im not gonna bash it, it looks really interesting and more dinamic than on the first game
2. the problem of the new economy system is its lack of logic in some areas, and its something that IMO is present in both games,in SR1 not all planets were designed to become jack of all trades, some planets had better resource amounts or had better features for certain types of cities and it was interesting, however, there was a lack of actual trade because all the planets could in theory grow the same facilites alltogether, so in that regard SR1 suffered from lack of complexity in its economy. SR2 does the complete opposite, instead of improving the bases of SR1 it takes out the planet uniformity and opts for a system focused in different types of resources, leading to strange cases where for example, from both habitable planets, there's one which exports only fruit, and another that exports water, ironically with both planets being of the same category. yeah, some planets would have a requirement of certain resources (gas planets would need to compensate in terms of not having soil at all, barren planets being forge/mine worlds with a strong dependance in stuff like water or food).
a middle ground between SR1 and SR2 would have been better in all aspects, not all planets would be fit to construct certains facilities and would require trading between them, but they should be able to produce certain common stuff without any issue, and each planet should have different types of resources avaliable. something akin the EVE Online's planetary interaction would have been an interesting approach. allowing for example to have habitable worlds that are better suited for the production of food, adapting to focus in certain products like apples, or gas giants that are stripped from their atmospheric components for water, oxygen and the like.
3. the tech system has the same splitted feature, the SR1 tech tree while limited was interesting in which you had to invest research on certain connections between certain fields to open others, the downside was the exponential increase of the research required for lvling in order to get to certain technologies, specially those endgame oriented like ringworlds or planet thrusters. SR2 seems to avert this in the way that it produces research over time and its not spent at random but instead each technology has a cost, i like the approach this time, but it could improve in terms of the bonuses, as it seems you can only research a tech once, the first game allowed you to research a field indefinitelly and improve all aspects of the tech. again, in this case a middle ground between the two would have been better. have a tree similar to SR1 with each tech branching into the individual developments and allow players to invest indefenitely their tech points into specific technologies, not have a single bonus once reached certain tech.
4. the building system is a middle ground too. i didnt like the approach of SR1 with the +/- scaling and the limited space to design your ship, however, i liked its focus in the balance between the keypoints of a ship (like its bridge, powersource, ammo localization, etc) and the many different modules i could put on my ships. the hexbased system of SR2 looks like the freedom i was looking for in terms of the ship's physical design, but it could have kept the modules of the first game. in fact, it could have given more emphasis into how do you worked the internals of the ship instead of just placing moduels in a grid, they skipped the oportunity to design a system where one had to actually care where do you were putting stuff like the engine, the crew quarters or other module (kinda like Wayward Terran Frontier but you could fully design bot the ship's mesh and its internal composition)
oh and one point, if you're talking about engines in regards to the ship's thrusters, each engine in SR1 had different roles, not just plain acceleration, one engine was better for reaching top speed, the other was better for strafing/changing direction quickly, and the other was fuel efficient but limited in output, there was other but i dont remember.
5. yeah it seems ship have better orders now and the physically simulated ammo is a plus, i dont know about the centralized ammo/fuel stuff but i like it as an empire wide solution which was something needed in SR1, still having an improvement in regards to ammo/fuel consumption for ships in outer space would have served to improve the popularity of support vessels (something akin to Rise of Nations supply units would have been a good addition).
6. i dont see many details regarding how FTL is handled, guess its the same like ammo and energy in regards to gameplay (empire wide collected and is consumed by every entity same way fuel is used) i dont see the problem with that i guess.
7. the artifact system is a plus in the game
8. planet lvls are a good adition but with the economy system it has i dont see the use for it, maybe if it was tied to terraforming (barren planets are lvl 0 and you invest to make it habitable, each progression into that would increase its lvl and would allow for producing certain products more easily, it would be expensive though).
10. i understand the need to put specially gameplay mechanics into different races but part of the fun of SR1 was designing your own, this could have been improved, like making players choose certain mechanics for the race they wanted to have, in fact, many of the things the different races do could have been added via the tech tree or something similar. and would take out the need to obligue players into playing certain factions for certain gameplay stuff. they could just make a race with X and Y attributes on its culture and select the key mechanics they wanted. stuff like motherships and biotech could be part of the tech tree TBH, it didnt need to be part of a single race.