Sneak need an improvement, not a drastically improvement like in the old days, but may be an adjustment to the formula. Also it would have a bonus in night. And also a bonus to PvE, not only PvP.
As a thievery skill i think that would give a bonus to not be detected by guards when you fail stealing, or some other kind of bonus to steal.
Other think that I don’t understand is the FoV. If it only works for detect sneaking players, and that players already have the direction penalty, a player with 10% in sneak will have almost the same sneak area that a player with 100%. So let the FoV a circular area, and the direction penalties and the sneak value will determine the sneaking area.
i know that in the original fallouts a player wont be able to run and sneak without the silent running perk. but in this game sneak works different, so i think an improvement to sneak would be: if a player is running and sneaking it will suffer a penalty like 25-35% (reducing it, not subtracting). Silent running perk will remove that penalty.
And for last, original fallout games have a support for an assassin/ninja build. i remember in F2 killing a enemy without alerting his friends. (and also the silent death perk)
So, for unarmed and melee combat I suggest that entering in combat mode won’t remove your sneak status but reduce it in 40%-50%. Obviously, the player that you are fighting can see you, but may be his friends won’t notice what is hitting him..
Feel free to post your suggestions about sneak.