Ultra HD is 4K, so this is not an alarming limitation. I will probably start shooting in "Full HD", i.e. 1080p which should let me make my stupid mistakes more efficiently as I learn.
The "Studio" version is a one time fee of $295, This article goes into depth about what the paid version offers beyond the free version.
A warning. As many people do, I abbreviate DaVinci Resolve as "DR".
Tom's Digital Photography Info / tom@mmto.org