I thought it was a cool idea but it killed me to be forced to put buildings in suboptimal locations and have to come back later with terraforming to make adjustments. It might be better just to have the tiles that give bonuses for putting certain building types on them.

Adjacencies are a huge pain and one of the things I like least about GC3 for reasons already mentioned. 

I like the adjacency bonuses. It rewards consideration on what buildings to place where, rather than just plop stuff down in any position and the terraforming tiles are also another good consideration the player has to make. Anything that invokes player decision making and rewards good decisions is usually good imo. If they can come up with something better or refine it great but I think it's pretty good for the most part.

I Like them.

I hope they stay, though with some modification.   I think that it is silly that the game restricts which spaces we can or cannot build on in a warp science capable society...

I think the game would be much better if each planet were such that you had X many usable tiles that the player plopped down.   Unique planet things could be surveyed prior to plopping... or randomly discovered.   But the player always had full control over where they built.

Then I also think that the bonuses maybe need to be less, or have things that unlock them for more.

The biggest issue with the adjacency was that it punished you if you didn't do it because the bonuses were honestly larger then they should have been.

I have mixed feelings towards adjacency bonuses. On one hand it is kind of fun and adds challenge, but I think it clashes with the RNG planet generation. Personally, I think it and planet development both need to be reworked.

I like micromanaging my first 5-10 planets, but it is pure torture doing it for hundreds (or thousands) of planets. I'm curious to see how GC4 handles planets and galaxies, because I felt GC3 was strangely enough too small (but still too overwhelming with micromanagement).

I almost wonder if terraforming should be reworked. Like instead of opening up usable squares on the map, it either changes the planet globally or allows you to utilize hostile planets.

I do like the idea of zoning planets based on terrain and specialization (eg, you have a part of a continent that is grassland, it becomes a farming district, etc), but I'm not sure it works when lined up with a geographical map, adjacency bonuses, and buildings. One side of me finds all that very appealing, but another side finds it very frustrating too. A side of me prefers having buildings all just being in the capital, but they do work nicely with adjacency bonuses. I guess what I'd probably like would be a cross of MOO2/GC1 and the zoning of GC2/3 and MOO3.

I'd almost prefer zones to be more abstracted where its not directly tied to the geography of a planet map, but tied to the planet size/habitability instead (eg, a small arid planet you'd get 2 rocky zones, a medium terran you'd get 3 fertile, 1 rocky, etc). Maybe terraforming can be used to change the type/quality of those zones.

I think a more simplified form of zoning would work nice for non-major (resource generating) planets. Just zone it, forget it, and move on to the next planet.

In GC2 every planet unless it had an event that made it special was built the same way. In three you had to think about what a planet was gonna do based on how the tiles looked and what bonuses where there. It added something to the game IMO, but of course it could be overwhelming at times. We should remember the number of planets under direct control are suppose to be less in this game. We won’t be planning the building lay out for +150 planets but only core worlds.

I think adjacencies as problematic as they can be should remain.

I’m definately on the pro side for adjancency bonuses. I would like to see the manufacturing bonuses more kind of like two. I’m not saying getting rid of adjacencies here, but even with them the manufacturing bonuses on factories are only good for the hubs, and that’s it. I’m not saying like they had before in three where all the buildings had the same bonuses, and then they gave us adjacencies. There needed to be a balance back then, but when they balanced it they kept going. What I’m saying we have something like with six adjacencies that the manufacturing is something like in two with a antimatter power plant, and six factories. Not so week like now. 
as far as micro management goes I like to play something like 50 planets in three micromanagement is not overwhelming. What got me about the wheel, and is getting me now. There are times in three when you could double click when instead stardock makes me use a button. I’m not saying remove the button. I’m saying have both option. One example is like when you pick a mercenary. The planetary screen when removing, and building improvements. Let’s first deal with the obvious micromagent solutions first. Before we dummy down the game without making quality of life improvements.