When I set my settings high (1920px - 1080px, 300ppi, RGB 32bit) I can't photoshop anymore... I can't make a new layer, I can't unlock the background, I can't do pretty much anything.
In Photoshop 32-bit mode restricts some operations and allows only some adjustments and adjustment layers be used. The dimensions you indicate are not particularly "high". I was able to create a 2000x2000 pixels 32-bit image with no problem and the adjustment layers shown in the enclosed image shows the ones that are not available. Also look under "Image/Adjustments" menu to see other directly applicable adjustments to a layer. If you cannot do these things then there is a problem with your Photoshop installation.