all your questions have simple answers:
-both pre sections you have found are exactly the same. Only the “acces” place is different. But, watch out: in your second image the pre section is not in the equalizer section. I know, they are together, and exactly that gave me headaches in the past, trying to understand why, exactly as you are now. Some people (Jedi master Chris Selim, see videos below) helped me in the past and now I try to help you. The pre section is independent of the eq and eq belongs to channel strip. Pre section don’t. For example, you could change channel strip position (eq included) to be pre inserts instead of post inserts. The pre section always remains pre ALL, but you will continue to see it together with the eq. It is not, “path wise” speaking. If you think Cubase is confusing here and manual is not 100% clear I say you are right.
Regarding VU meter, no, for gain staging I wouldn’t use VU meter nor master LUFS meters of the PRO version. VU meter gives you RMS reading and some of the very good master meters give loudness reading (similar with RMS, although not exactly the same). For gain staging you need the simple peak reading that you have in your simple channel meters. They are noble! They are fine and beautiful! You need to aim for an “eye mean value” of about -18 dBFS. For example, you could have a very dynamic recording where with your eyes you see that the reading is reaching several times levels of about -5 dBFS but your RMS reading of the VU meter gives you just -15. In this case, with the VU meter you wouldn’t move the gain, but you need to! VU meters and LUFS meters are great valuable tools, but not for gain staging (I have seen some gain staging tutorials where VU is used, though). You will need LUFS and RMS in another context, for example mastering. There they will be the kings.
-Regarding channel meter position: yes, you can set this up. Reasonable would be to set it at input when recording. I don’t care so much, as I set pre gain and fader at 0 at recording and adjust just interface gain in this stage.
-Regarding your last post: it is difficult to tell you if this level is too high, because channel meter is peak value, so what I see there is the exact instantaneous level that audio had when you took the picture and not an “eye mean” value. Please see the readings and if you find those levels are approximately a mean value that you see, then yes, you can solve that simply by lowering the pre gain, provided that your audio has no defects, for example a clipping. In this case you would need to record again. If this is not the case, simply less gain and The End.
I let you here an old video about gain staging from my favorite mix channel. That would be the after recording stage, but you can apply same concepts to the recording stage
And another, newer one