Alright, so allow to preface this by apologizing for the vagueness contained herein.

I have previously worked a bit with the Oblivion Construction Set (primarily in regard to editing levelled lists and locations), and have recently been reading through some tutorials on how to do the same in the Skyrim CK (and I've been successful so far). However, I have decided that there are a few mods I would like to make that involve overhauling certain gameplay mechanics (which is something I've never done before). I looked around for tutorials on this kind of thing, but wasn't able to find much. A few specific questions I solved via google (all hail google), but that's been the extent of my success in this regard. I'm not necessarily looking for answers to specific questions (although those are more than welcome ) so much as a pointer in the direction of some good resources I should read/watch on this. I DID look through the stickies, especially the one with the big list of tutorials, but I don't think I saw what I was looking for. All this rambling aside, here's a handful of things I'm hoping to accomplish, mostly involving what I can only assume are referred as global variables:

• Alter health, magic, and stamina regen rates on both the player and all NPC's in the game (I think I understand how to do this for the player at least)
  
• Modify the the effectiveness of specific alchemical effects in player-made potions (for instance, make all stamina potions restore TWICE as much stamina)
  
• Alter the algorithms used to determine the values of these potions based on their effects (say, player-made fortify health potions are half as valuable)
  
• Alter combat algorithms (specifically involving how stamina effects damage)
  
• Alter player and NPC speeds based on stamina
  
• Change certain effects (from potion or spells) to cause a certain PERCENTAGE of damage, as opposed to a flat amount.
  
• This is the weird one (I think):
  This will probably involve muchas Papyrus, and as such I could probably figure this one out via tutorial if UI spent enough time, but since I already made you read my other questions already; I would like to create an effect and apply to certain consumables (not necessarily craftable in alchemy, just placed on items by me via the CK) which will prevent all Stamina, Health, or Magic from outside sources during its duration WHILE SIMULTANEOUSLY draining this stat. (i.e. for 20 seconds your stamina will not be drained by power attacks or sprinting, however over that time you lose five points of stamina every second).

For a handful of these, as I've already mentioned, I could probably find a specific "You accomplish by doing " time answer already, but I'm really looking to understand how this stuff works. I realize it's a lot to ask someone to explain all this, which is why I'm mostly fishing around for good resources explaining this sort of thing that already exist.

Thanks for taking the time to read all that, and I appreciate your help!
~Connor

Alter health, magic, and stamina regen rates on both the player and all NPC's in the game (I think I understand how to do this for the player at least)

Pretty sure you have to mod the base actors/races' Actor Values for this. Individually.

Modify the the effectiveness of specific alchemical effects in player-made potions (for instance, make all stamina potions restore TWICE as much stamina.

Open up the Ingredients section of the CK, crossreference with the Wiki for all the pertinent ingredients, double magnitudes.

Alter the algorithms used to determine the values of these potions based on their effects (say, player-made fortify health potions are half as valuable)

Same dealie-o here.

Alter combat algorithms (specifically involving how stamina effects damage)

That is going to be a lot of scripting to make decent and I don't recommend starting here. But perks w/ entry points that mod attack damage multiplied by stamina AV would be a start.

Alter player and NPC speeds based on stamina

Eh... same deal, use a perk to mod spell magnitude of a slow effect based on stamina? Or scripting.

Change certain effects (from potion or spells) to cause a certain PERCENTAGE of damage, as opposed to a flat amount.

Percentage effects always have to be scripted and I'm not sure you can do that with player-made alchemical concoctions.

Sorry for the brief and non-comprehensive answers - I'm better with magic effects. Welcome to modding Skyrim, though.