Vias don't have thermal reliefs, the purpose of thermal a relief is to make hand soldering of especially THT components in large copper planes possible, without the need for a really powerful soldering iron.
This is not a problem with reflow/wave/etc. soldering.
Never seen that practice as vias usually are covered with soldermask - which is the next problem you would need to solve, vias don't have soldermask clearings..
That covers Q#2 of yours, back to Q#1..
You might want to try OpenGL canvas then..
(screenshot from nightly version)