I would avoid 50JK (50J is really not a good place to be) and 56JK (galley noise).

59AB and 59JK both have direct aisle access for the window seat passenger if that is particularly important to you. One potential downside is that you will probably be served at the end of the service cycle. This could be more of an irritation for the main meal than the second meal, especially if it will be breakfast after an overnight flight (when you might want to be woken later rather than sooner). Personally, I would not allow the possibility of a baby being in the bassinet on the other side to sway my decision much. IME, babies in WT+ are generally well-behaved and quiet.

But personally, I would pick 52AB. I don't mind stepping out from the window seat (nor have I had many problems from others stepping out over me when I've been in the aisle seat). And IME 53B can be one of the last seats to be occupied because it's got so many disadvantages, so several times I have actually had direct aisle access from 52A or 52K.

The stepping-over doesn't work quite the way you describe. If Mr Fink is in 52A and you are in 52B, he will step out over 53B, not over you. It will be 51A who steps out over you.