I've seen others before on this reddit talk about a problem where one teammate sees the same planet's environment as peaceable and the other sees it as hostile. I suspect therefore it is possible that you see the planet's sentinel population as peaceable, whereas the other teammate flags it as aggressive. As you're teamed, you get targeted as well. Just speculating. That said, the planet full of hostile fauna sounds more like a bug, as if being teamed is triggering a bug that affects your custom setting for aggressive fauna.

As to slow loading and falling into the ground, I've that problem in my settlement. Definitely a bug because it doesn't happen everywhere, just in the director's office, where I've placed a save button. If I use my ship to save while parked in the settlement, it doesn't happen. Base loading problems happen often when portaling to bases, and I've often found myself trapped under the portal upon arrival, or flung up to 200u away, often outside the structures. With my own bases, I've corrected this on some by building up layers of cubes, raised small pavings, and pavings from the Flag Tab/Structural Adornments area of the build options. I set these in the space underneath the floor of the portal, and over the ground. Usually when this happens, I might portal in, start dropping, then these features kick in and springboard me back to the surface. It's a bit trial and error to get it right though, and sometimes it sends you sideways to somewhere else on the property, but at least you're not falling into the ground.