Long version of the idea can be found http://www.gamesas.com/topic/1338190-activities-that-freeze-time-and-those-that-dont/page__fromsearch__1.

Short version of the idea: Having time pass whilst in menus, with the SYSTEM menu being the only exception. The system menu would pause time so you could go and get a Coke or take a leak with the game paused so your character didn't die, but time would keep passing while in any other menus, so it would be largely impossible to spam potions, change armor and the like as a zero-time action in the middle of combat, and you'd be well advised to make sure your surroundings are safe before consulting your map or a book.

I asked if any such mod existed http://www.gamesas.com/topic/1396211-has-anybody-made-a-mod-where-most-menus-dont-pause-time/, but it doesn't sound like one does, and I got some people saying it doesn't sound likely that such is possible.

So here's the nut of it; can menus and pausing be separated? Is there a way to pause the game that would only allow you to enter the System menu, but prevent you entering other menus? Could those other menus be called up while time continued to pass?

I think with all the interest in hardcoe mode mods and the like that there might be some interest in my idea, which would force a degree of tactical thinking by removing the ability to spam potions, wear a set of sneak-enhancing clothing and then magically switch to full armor in zero seconds if spotted, forcing people to be aware of their surroundings and realize that they can't just glance around the map forever or re-read that book without checking their surroundings every so often, and so forth.

Anybody know about this? I'm still very curious about this idea, and I'm hoping there isn't something hard-coded into the game engine that would make this impossible.

Pausing puts the game into menumode which pauses time. All of that is hardcoded. You could possibly kind of access some of it with some advanced SKSE stuff, but most of it is hardcoded and can't be changed.

Urgh. That's too bad that they linked the two things at that level. Would have been nice to have the two things, the menu system and the pause function, accessible separately. I suppose I could look into scripting, but I don't know the first thing about scripting. I'd be starting from scratch.

The only workaround I can think of would be to remove items upon being equipped/used etc, then activate them with a delayed script in GameMode.

So you'd activate a potion/armor whatever in your inventory, it'd then remove them from your inventory and add them to a script/hidden container. Then you'd drop out of the menu, and they would go into effect after some delay, an animation, or just disabled player controls for a few seconds, leaving you vulnerable.

I don't know how you'd do this with potions since they're used up on activation. Does Skyrim have the Max Potions at a time field in globals? I haven't checked that.