http://www.youtube.com/watch?v=un7X0FXSdpI&feature=related - a simpler way to explain things
http://fallout.wikia.com/wiki/Lockpicking
as for how skill comes into play- your skill allows for a wider area to position your pin correctly. for example if you had 100 lockpick (or sneak if it gets merged <_< ) and the lockpick was level 15- you pretty much wouldent need to move the pin and only have to rotate the lock. however if the lock was level 75, and your lockpicking skill was 75, you would have to be correct within a degree. if the lock was level 75, and your skill was level 74, the game wouldent even let you attempt because of there being no acceptable angle to put your pin.
however- multiple minigames would be very nice.
but, even with minigames- the old morrowind idea of better lockpicks should be thrown in to assist the player in harder locks. (apprentice,journeyman,expert,master and grandmaster) (but we do NOT need the skeleton key again, that thing just made lockpicking pointless)
perhaps if there were different lockpicks then there could be a much larger gap for lock levels (instead of 1-100, we could have 1-225)(aprentice could offer a 25 bonus to lockpicking, a master 100 bonus points, and a grandmaster 125)
lockpicking should run in real time. if the player thinks they will get attacked whilst lockpicking, it would be tactical to summon something to cover them
sneaking
if an npc knows the player is invisible, they should try swinging around if they are doing well. if they are scared they should probably run/jump around nervously. if they have spells like detect life they should use that, and if they have a good sense of smell they should be able to attack easily, although be a little confused
every mellee weapon (including fists) should be able to do sneak attacks.
there should be spells that dont make a stupid light on you. the player should be able to make spells that use more magika but dont give away the players location.
we need....
spells to make the area darker (and that would also really cripple moral)
spells to make the player walk on WALLS
spells to create sound (anywhere the player wants, to distract the enemy)
spells to make an enemy silent (so they cannot scream for comrades)
spells to blind an enemy
spells to make an enemy feel sick
spells to make the enemy see things
spells to stop smells (so that monsters dont snif the player out)
spells that allow the player to pick locks whilst being far away, however- this should make the minigame harder
also- animals should be able to smell the player. water should help camouflage the player (both in and out). people should have many different reactions to the player sneaking around- from getting more scared to more angry.
wearing certain armour should also effect the players ability to sneak. some heavier armour should make noise