1)  Yes, a setting of 720p should apply to medium view.  I sometimes use this setting at 60 fps.

2) Will higher bitrate increase quality?  Yes, a higher bitrate should increase the quality, though I have not done side by side comparisons.

3)  For a little higher quality, use 1080p and either 30 or 60 fps.  Depends what you are trying to do.  For normal play, I use 30 fps.  If I’m interested in checking line calls for whatever reason, I will put it on 60 fps.  I personally use 1080-30 for almost all of my videos, along with normal bit rate.

4)  I  edit my videos using FinalCut Pro before uploading to YouTube.  Unfortunately I have never used the tools on YouTube, so I can’t really comment on that, though I know there are some basic functions.  For some free editing software, you might try the GoPro editor that is free online.  Here’s the link.https://shop.gopro.com/softwareandapp/quik-%7C-desktop/Quik-Desktop.html    I’ve played with it a little and it seems to do a good job.  There are others out there like this one:  https://www.blackmagicdesign.com/products/davinciresolve/    I haven’t tried it but it looks pretty good.  There are others out there, many for under $100.00.  And new ones come out all the time.

Hope that helps!