4K 24/30 or 1080 60P?

One of my hobbies is filming rock concerts. I'll record 2 songs (give or take) at each concert I go to, from my seat. At times, I may be far away from the stage, sometimes on the opposite side, in a large stadium. I like certain characteristics of 30fps and certain characteristics of 60fps. But if I were to have to pick only one, I would choose 60fps. My camera does not have 60fps in 4k. So if I am too far away from the stage, the 8X optical zoom may be just a little too short, so I change it to 4k, and then in post I will crop in on certain segments of the song. If I stay within a 2X crop, it should be on par with 1080 non-crop.

What I don't like about 24/30fps is sometimes the footage looks jittery, especially if I need to move out of the way when someone needs to walk past me in my row or when the audience is jumping up and down, which causes the bleacher seats to vibrate. Of course 60fps will be also be shaking around under these conditions, but not the jittery kind of shake. I follow the 1/(fps x2) shutter speed rule. Can changing this SS help out with the jittery footage? What should I set it to?

Also, I was told that I "would get better image stabilisation and sharper pictures in low light at 1080p60" than 4k 24/30.  I don't understand this.   4K is sharper than 1080 and 60fps limits my SS to 1/60 but 30 fps is 1/30 (ideally 1/120 @ 60P and 1/60 @ 30P) , so more light with 30P.