Well no matter how many times you moved around the ogre he would only get one OA as its his reaction. If you could get him to spend it on something else
But by the rules you can move through allies squares I am just not sure you can move into an occupied square, attack and move out of it again...
Sure, I think that seems reasonable, so long as you don't end your turn in an Occupied square. So if Kelvyn moves back (and I am not sure if Scotely is still busy I can NPC him) and Uhtred charged forward 10ft and then moved back 5ft if you don't succeed that would work BUT the ogre would get an OA against Uhtred I believe (moving back). But if you did this I would give Tirion advantage on the Shovel maneuver...