Those are my videos
Often the whole process of Video Astronomy (or EAA as it gets called in here) is explained in a very complicated way.
It really is simple.
Wack a little camera into the scope, plug the other end into a TV or monitor, and BINGO! Live Solar system objects and Near-Live DSO's.
Yes, I use a $1700 EQ mount. But you don't need to. A basic Alt/Az will do. All it needs to do is track, and not even accurately.
That 120mm Achromat you mention that I am using in the video, is a pretty cheap scope. You can even use a simple little 60mm Achromat if you want. Aperture doesn't matter with Video Astronomy. Your ETX will be ok to use.
You don't have to worry about accurate tracking, or field rotation, or bumps and knocks to the mount, or thin cloud, or wind, or light pollution.
Because these cameras are very sensitive they catch views in a very short exposure time (often called sens-up).
For Solar System objects you would be using settings like 1/500th of a second, so it would be instant video like with a webcam. So any movement in the mount doesn't matter. In fact, little movements add to the 'Live' experience.
As for DSO's you will need to lengthen the exposure times (sensup) anywhere from 1 second to 5 seconds. You don't need to internally stack. You don't need a computer. You don't need to do anything except go to the object and see it on screen
In one post I notice that you (or someone else) explained Alt/Az tracking as up a bit, to the right a bit, up a bit, to the right a bit, like a staircase. No, not exactly. Alt/Az tracking is diagonal. Both Alt movements and Azimuth Movements happen simultaneously so it is a smooth graceful diagonal tracking.
The only time you would notice any field rotation is if you were to stack several longer exposure frames. And even then it wouldn't be much. Not like long exposure Astrophotography.
I made some graphics for my website to show how easy this is to set up:
With a Monitor or TV
With a Computer
( I think Mike at Revolution Imager supplies a Video Grabber so no need to buy one)
With a USB camera
If it all still sounds too complicated, there are a lot of Video Astronomy beginners getting help with really helpful tips and answers at a Forum devoted totally to Video Astronomy HERE
The camera settings for the Revolution Imager, and other Analogue style cameras are pretty easy and even though they have a lot of options to fiddle with, you'll probably never us many of them. You only need to choose a few settings.
It all looks and sounds complicated at first, but relax. It is really quite simple.
I hope this helps