This is the link to a build I am planning to play on master difficulty
http://skyrimcalculator.com/#10609

Race will be Dark Elf
I dont want any crafting perks.
The plan is to sneak around and assassinate and then let some magic fly when necessary.
Looking to create a viable but also fun build without been really OP.
I would appreciate any help off people who have played in master difficulty and where the drawbacks to my build might show up.
Also what way I should allocate magicka, health, stamina
Thanks in advance

You plan to sneak around and assassinate targets but have no perks in sneak for backstabs or improved sneak?

Also, you said you don't want crafting perks but you have 16 of them

I'd recommend getting rid of Soul Squeezer and Soul Siphon from Enchanting and just getting the Black Star from the Azura daedric quest.

You have a lot of magic perks, depending on what kind of situation you see yourself in, a lot of Magicka would be ideal, also given your an assassin Id imagine you dont fancy long combat, so stamina isnt so important, Health and Magicka are my opinion. kill quick live long.

you will never get 81 perks

I don't really understand these threads where someone has chosen 81 perks....

The ORDER you are able to take the perks is far more important than what perks you will have at level 81.

Also agree with others that the character you posted doesn't match your description....

An assassin-thief type with spells replacing archery is a viable character build. The illusion perk silent casting is a must though, and you aren't taking it and aren't taking any sneak perks either.....

Sorry, please ignore the build I have lonked to the wrong one, doh!!!