Came here wondering if ToS is even worth it. I've already built it, and other players have given enough KP to get it nearly level 3. Although the extra Supplies are nice per scout, I could easily gain what ToS puts out with just one 15 minute production in one workshop. At this point ToS seems like a waste of space. Definitely thinking about deleting it after rewards are collected for the level.
Also considering deleting Endless Excavation. I have no problem getting relics since I participate in the tournaments every week and get far more relics that way than I do by completing provinces, even with EE.
Golden Abyss is fantastic. It only takes up 9 squares, and level three gives almost as much population as a level 15 residence, at level four it will give even more. It's pretty too, so definitely a keeper.
Don't have Needles of Tempest just yet, but seems worth it for the training speed and light unit boosts. Are there any disadvantages to this one? I can see how it would be useless to a player who doesn't want to fight in the game, but is the benefit to a fighting player worth it?