Ooh, ooh! A question I actually have some experience with! How exciting!
I use my Mac laptop to run the MPCNC as well. I believe the tutorial to either be outdated, or RepetierHost on Mac looks much different than Windows. Possibly both. The tutorial could just show an outdated version of the program.
The only way I have found to manually control the axes is through that tab you talk about, which also has options for extruders, feed rate (speed of movements), and other stuff that doesn’t appear to apply unless using an extruder. So I will click click click whichever mm distance I want the selected axis to move. After using a 3d printer with an LCD and dial, it is definitely smoother to move any axis that way. I am going to set up a Raspberry Pi with the awesome V1pi image Jeff made, however, otherwise I would absolutely get an LCD for my MPCNC.
As far as ESTLCam, it is much easier to use than Fusion 360. I wanted to use Fusion because it is free and available for Mac, in addition to being a 3d modeling software. I think I got a few 2d drawings, for plotting, to export some gcode that ran on the machine, but that was after a lot of additional time spent learning how to get Fusion to even EXPORT anything because of the stupid tool path and tool selection settings always seeming to conflict. It took too much time, or at least much more time than seemed necessary. Especially for a drawing - it should be as simple as importing the sketch, MAYBE setting line widths, selecting lines (the only area ESTLcam may be lacking in because for sketches with many lines, you have to manually select every single line whereas I think Fusion allows drag selection), then hitting export gcode.
I’m lucky because I have other computers in the house that use Windows, so I set up Microsoft Remote Desktop on one and my Mac, and installed ESTLcam on the Windows PC, so now I use a shared network folder on that PC to drag the raw files, and run the remote desktop to use my Mac and work in ESTLcam to get the gcode, put it back in the shared folder, and retrieve it on my Mac to run over USB to the MPCNC. V1pi will thankfully cut out the second half of that, so I only have to go from here to the Windows PC. If you cannot access another Windows computer (maybe even look for a super cheap laptop?), maybe you have more knowledge in setting up virtual machines and can side load Windows in something like VirtualBox. I tried, but probably didn’t invest enough time to actually figure it out. I gave up and realized it would be easier for me to use remote desktop since I had another PC available.
I hope some of that helps!