Playing stealth on Master seems almost pointless to me. If you oneshot every enemy, it's no different from lower difficulties. If you don't, it just makes you have to stop playing stealth and start playing melee or magical direct or indirect combat instead. If a hybrid character like that is what you want then fair enough, but pure stealth on Master, I dunno. It seems like it would either just remove the satisfaction of successfully assassinating your targets in a clean blow, or force you to alchesmithchant a bunch of stuff so you can do it... and make the game no different from what it would be on Adept without having to spend hours leveling crafting skills.
Let him be king over charred bones and cooked meat. Let him be the king of ashes
Mages are actually very easy to play at lower levels on Master if you know what you're doing.
If you do go mage, focus on leveling Destruction and Conjuration early on until they are both at least 25, then grab the Apprentice level perks for both (you can do this by level 5).
Get the spells Firebolt and Flame Atronach ASAP.
Flame Atronach can be gotten for free from Faralda at the College of Winterhold (save infront of her then reload until she gives you Flame Atronach).
Staves of Storm Atronach can be made at the Atronach Forge in the College of Winterhold midden at ANY level, just collect a Grand/Greater Soul Gem, Broom, Void Salts, and Orichalcum Ingot/Ore(they DO NOT require a Sigil Stone to make).
Lydia is one of the BEST followers for a low level mage get her ASAP as well.
Adept Robes of Destruction can be gotten from Marcurio in Riften even at level 1 ( just use the Ice Form/Pickpocket trick to get it off him).
Also, TC another mage tip I forgot to add is doing the Blood on Ice quest to get the Necromaner's Amulet, it gives you 25% Conjuration cost Redux and +50 Magicka, perfect item for a low level mage character.