Thanks guys,
this is gonna be awesome. First chips!
I took some time to at least get the x-axis travel not all woggly, threw in a crappy lathe toolbit shim to bring it ~0.002-3 from one end of the table to the other - good enough to get started!
Then I discovered what my real first project is going to be - cutting some t-nuts to properly fit this little vise! You can see my very unorthodox clamping setup below... And apparently I haven't the faintest idea how to use a clamping set - and the set that came with the mill has t-nuts and bolts wayyy to large for the t-slots in the mill table. I also have no idea how to clamp stuff in general. Going off of YouTube memories, that's the best I came up with, but I would imagine clamping on ground surfaces is a no-no. Did not see any other way to clamp it, however!
Grabbed some lathe cutoff stock (1" mild steel), used a t-nut as a parallel, and went to town with the biggest endmill this came with (6mm). I very very gingerly took the facing cut, probably only 2-3 thou, but it cut like butter! Then I cut a light (5 thou) simulated slot for funzies.
Some things for me to address - the y-axis is still off - about 6-8 thou front to back, so you can feel that in the facing cut - not jagged, but just enough ridge for your fingernail to bump over.
Anyways - this was totally worth springing for, so glad to have this door open to me! \o/