I'm not sure if this would be possible or if it would even make a difference but would it be possible to create a spell/power/shout/enchantment that gave you the ability of Dark Vision like in Dishonored. Dark Vision is an ability that does several things (several of which I know are already possible) that allow you to have a heightened awareness. It allows you to see in dark places (night eye), to see people through walls (detect life), and most importantly to see their field of vision in a cone shape.

Now I remember seeing several mods that tweak the field of view for npc's but would it be possible to highlight that field of view? If so would it even be beneficial to to the player with the mechanics in which Skyrim handles stealth?

Dark Vision: http://www.bagogames.com/wp-content/uploads/2012/10/dishonoreddarkvision-e1350039479979.jpg, http://nowgamer.net-genie.co.uk/siteimage/scale/0/0/343873.jpg

i would like this very much, actually all the dishonored powers as shout powers would be amazing, the rat swarm, blink, the heart that lets you locate runes and bones [have it locate rare treasures and comment on the game world]
and of course...mantling and leaning, staples of the first person stealth game.

Well, we have blink spells already, I'm sure an enchantment that forces npc's/creatures to turn into an ash pile would be possible, eventually toggle jump height and speed spells will be possible (hopefully), leaning would be pretty nice as well, I know that MadMole is going to have a summon skeever swarm in his vampire mod. An ability to have a detect treasure/weapon/tome/scroll/artifact/key spell would be pretty cool as well.