It's basically an all out utility build that gives a lot of fun ways to kill enemies and centering on Alteration. This means I won't be wearing armor.

I've basically thought about what would be the most fun, versatile way of playing. I haven't tested this yet in any way, so I'd like some comments.

Race: Breton (25% magic resist adds up nicely with alteration) or whatever

Stats: +150 into Health/Stamina, rest in Magicka (just an estimate)

Perks (80 in total):
Alteration: 14 (full)
Conjuration: 15 (full, I'm intending to use the Bound weapons a lot)
Sneak: 8 (1 in base perk, left path complete, right path until bow perk)
Lockpicking: 6 (just what you need for "no lockpick breaking" perk)
Pickpocket: 6 (center path, plus the one that gives +100 weight limit)
Speech: 7 (base perk maxed, plus 30% extra persuasion, I prefer it over intimidate anyway)
Alchemy: 15 (many points here, but it seems so cool. I'd max out illusion if I left this out)
Illusion: 4 (what you need for quiet spells, this seems super important for the sneak part)
1-handed: 5 (base damage)

A second version would skimp 5 points on Alchemy and 4 points on base Speech perk to max out Illusion. This would weaken the potions and decrease gold income (which I need a lot of if I want to train all my skills to 100 within a lifetime) but a lot of new tactics.

What are your thoughts?

You will probably have a very difficult time killing things. It looks fun but the new leveling system is very punishing to hybred characters. I would focus on either sneek and 1 handers first for 5 to 10 levels and then your magic. Since you are not going destruction and it doesn't look like you want to summon things (as it would get in the way of your sneaking and sneak kills) if you level utility along with your one damage ability you will find yourself hating most fights (dragon included).

One of the toons I've created has sneak, destruction, 1 hand and illusion (for the silent and lightless casting perk). It is difficult but fun, I've found either enchanting or smithing is a must, being able to double enchant items or improve them (or both as my orc warrior is doing) is almost a must at level 20+ while on master difficulty. I would say do what is fun but it seems Bethesda has taken that option oout of this entry as well...

I actually like the fact you think it will be hard. Maybe I'll have to use all my tactics from time to time, so that's not a problem to me.

Are you sure that summons take you out of sneak though, because companions don't. Maybe it depends on the summon? Even then I still think it's viable, because I can use bound weapons and defense methods from alteration to put a good fight alongside my minions.