All the HELP system is available online.
https://help.autodesk.com/view/OARX/2025/ENU/

And yes, you can use DUMP func to get a list of methods available for selected object.
(vlax-dump-object (vlax-ename->vla-object (car (entsel))) t)
Also TRANS function is there
https://help.autodesk.com/view/ACD/2025/ENU/?guid=GUID-1A316343-0B68-4DBE-8F49-B4D601CB8FCC
I used (trans pt 0 1) to transform coords for WCS to UCS. Those integers just identifies type of coord systems from - to. The function does THIS type of calculation - it's really a matrix calculation, reals to reals. As precise as possible.