I just got PC version of Skyrim about a week or so ago, been playing on PS3 as a fighter thief, pretty much a master of all trades.

My PC character is going to be a mage, any ideas of what crafting skills would RP well with a mage ? Any other RP ideas that will make this play more unique & fun?

Enchanting would be a start.

My advice would be to create a backstory for extra immersion. It transforms the game.

The RP depends on the race.

Also, what difficultly are you playing on? If you avoid increasing health as a mage, expert will be a good challenge against most enemies. But if you are trying to make an optimal build, master can be superior, but take cation, this can be very dull .

A Thalmor assassin who's mission is to wreck as much havoc as possible in Skyrim, and to kill as much of it's people as possible, without being noticed.

Use sneak, illusion fury, and back stabs on anybody you can, lure them somewhere no one notices them getting killed, but save beforehand, because they might happen to be essential, and you could not kill them.

Might have some fun like this.

Do stuff http://i.imgur.com/D2PvcSr.jpg

Search nexus for unlimited summons mod for starters. Feel the power rush through your veins.