1) Go into stealth
2) Become invisible
3) ???
4) Profit
But, for realz, just go into stealth and you are invisible.
As Drevis Neloren himself would've said it: Invisibility is tricky to master, but exceptionally useful.
You can be a Nightblade spellcaster. I know I will be. You have both the Destruction staff and Mage's guild tree, available so it should be possible!
You can =) NB can have a shade spell and if you go with a Dunmer you have an additional Ancestral Gaurdian. Although with Sorc you can have a couple more, but invisibility should be a good enough escape mechanism IMO. Remember you'd be using invisibility mid fight, since you'd likely enter it with stealth up.
AFAIK for survivability in NB you want to push the Siphoning tree for it's health returns. It's got some very nice heals with Siphon and the DoT. And the Shadow tree, which has all that invisibility stuff and the shade which you want, has HP bonuses. I assume that healing in ESO is % based a little so the more health you have, the better healing becomes, etc...
I honestly have no clue whether staves are 2H or 1H, unfortunately.
Precedent in MMO's would point to them being 2H, while precedent in TES games would have them be 1H, and I don't have access to the beta to be sure =[
Oh yeah that much I know we can. You know how weapon swaps work, right?
At a certain level, I forget which though, we unlock the ability to have two weapons "slotted" and a weapon swap instantly mid-battle is bound to a specific key/button.
Not only that, but each weapon has their own hotbar, which increases the amount of possible abilities we can use in battle from 6 to 12.
However weapons can only use their specific weapon abilities, so for example you'd probably want to tie you invisibility/shade/mage guild/etc spells to the sword, and keep Destruction staff spells on the staff and swap when needed.