I was in K1 lower Row I last year, about 3 seats in from the edge. It was a good seat, but the tunnel is a long way away so I wouldn’t say you see a great deal of action up there. You probably want to be almost half way up K1-K2 high to see it better.
Being in the lower section meant the fence was in the way for some of the straight, which I assume would only be worse for K2 onward. As you know, you want to be as far left (facing the track) and as high as possible.
If you put a gun to my head, I would lean towards getting the highest seats you can going no further than K4 over the lower seats.
Would you consider using a website like bookf1.com? I used them last year as I was late buying tickets and I’m glad I did. I have no affiliation with them in any way, they were just accommodating and willing to work with me around my specifications. It would be worth checking with them to see if they have any K1 High tickets.
Anyhow, the pictures on the http://www.formula1monaco.com website give you a pretty good indication on the actual view so make sure you check them out if you haven’t already.
Hope that helps a little. Unfortunately I can’t help you with your other questions.