Preflop I think it is fine to either limp or isolate. If it is one limper I definitely isolate but the hand is a decent one to take a cheap flop multi-way.

When the MP2 player bets 60/360 on this flop I feel it is usually a weak hand trying to buy a cheap shot at improving. Flush draws, straight draws, weak aces and weak 7s or 8s could all be in his range. I like the flop call as I don't think raising will achieve much at that point as better hands are not going to fold at these levels (particularly Ax type hands).

The turn bet being small still makes me feel he has a weakish hand. When you raise and he calls I still kind of think he might still have an ace, possibly a straight that got there and maybe a flush but probably not as big as yours unless he specifically limped with Kxcc.

The river bet he makes is probably just trying to get to a cheap showdown with an ace and I would raise here every time and make it a pretty decent sized raise as well for value. If he then comes back over the top then I'm probably still calling even though I might be beat as it will have been a very weird way to have played Kxcc or a set on the flop. Even the weakest players normally know they need to bet strong on the end with their monsters don't you think?