Desrtoying planetary improvements

You can scrap facilities on a planet and recover some of the materials used to create them. You'll find it under Cargo Orders. I believe the shortcut key is Ctrl+K.

And press the spacebar to jump to a ship that has no orders. You can also set up a view in the Ships window (Shift-S) which displays orders, and sort by that column - the ships with no orders should appear either on the top or on the bottom, depending on the sort order.

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The power of the ancients is now yours to command. You are truly the Master... of the obvious

There isn't a good way to upgrade to temporal space yards. You just scrap the regular one and build a temporal one (at a slower rate, because you don't have a space yard on the planet anymore). I don't like this, and have modded it so that the temporal space yard can be added to a planet that already has a spaceyard. The temporal spaceyard increase by a percentage the build rates (in my mod).

in stock Look at the difference in build rates for fully researched spaceyard vs temporal spaceyard. It's not very large.

SEV, more than a feeling.