Tiberius hard to disagree with you that from a certain point onwards Caesar was taken in a spiral where he tried to achieve more and more! As often as I tend to forget it, he still was a human being and power probably went to his head.
Still - and I know ome people here will get at me for that - I kind of subscribe to the school that sees JC as initialy wanting to be "primus inter pares" and not the sole ruler. But that's my own interpretation.
As for JC and Cleo... certainly he really liked the woman (intelligent, powerful, young and ambitious, a very appealing mix for anyone). I'm not so sure he really meant to impose Cleo on the Romans... somehow, IMHO, he wanted more to impose himself (read Rome) in Egypt than the opposite. Egypt was such a resourceful country and he was a conqueror... through Cleo he ensuered Egypt to Rome.

And... I'm willingly being provocative. ;-)