Good to hear you've found your balance. If it means anything, I would have suggested going pure Mage also, as being a Battlemage may have had similarities with your Assassin.
I've got two characters on the go similar to what you have also. My general rule of thumb when playing an Elder Scrolls game is to ALWAYS have an Argonian, and then a second character being the race that is native to where the current game is located.
So at the moment I have a Warrior-like Nord, who favors the 2H Axe, who also happens to be a Werewolf. And I have an Argonian Vampire who dabbles in stealth and all things magic, especially Conjuration.
I think they compliment each other.