1. Okay, so first case - some trees get invisible when I walk behind them and don't get back to normal. Currently I have two trees like that, each placed in unreachable area.
2. Second case is a bit more serious. From time to time I go venture around map to pick plants, berries, fragments etc., and sometimes when I open inventory it freezes. I can see the background (rain, my character) moving, I hear sounds, but for some reason inventory just doesn't react and I have to close game forcefully to make it work again.
Until now it happened twice, both times I went on a long trip west from my house to fill up my equipment with plants. Never occured in other areas or while doing other things.