You don't need a high altitude endorsement to log time in a King Air, even PIC time. You need it to act as PIC.

You also don't need to meet the requirements of 61.55 to log SIC time in a multi-crew aircraft (which both you listed are), as long as you are flying right seat to meet the requirements of 61.55 (per section (f)(3)). If that is what you were doing then log away!

If you had passengers in the back before doing 3 landings, CRM, aircraft knowledge, and single engine maneuvering you should probably refrain from posting that on public forums; let alone put it in your log book. That could get you in a heap of trouble logging it or not.