1) The AI in question had advanced storage capabilities, which allows you to build more facilities on planets than usual. Those facilities don't disappear when the planet is captured by other players that lack that advanced trait, but if you scrap them you can't rebuild them.
2) The crushed red can indicates that there's no spaceport in that system, and so any resources being produced by that planet are not being added to your empire's economy. You need to build a spaceport somewhere in that system, unless you have the Natural Merchant advanced trait in which case you'll never see that icon in the first place.
Re: Shrinking planets
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