Philips shape is the next step up from a flat head. Its just a double flat head sort of. It self centers and only requires 2 tooling motions if they are being ground.
The dont overtighten thing has always seemed like a weird misunderstanding that all bit types could be designed to do that.
Oil pressure tells you if the engine is dying or if the Oil is breaking down or overheating. I’d take it over an RPM gage.
A lot of vehicles dont have it in their cluster menus these days.