Currently working:

• Any ObjectReference can be a container.
• Any item can be added.
• Items can be any size.
• Containers can be any size.
• All items stay in players inventory
• Containers auto sort to try and fit items.
• containers can be placed inside of containers, so long as the container itself can fit inside. 
  • This may look like a big exploit in terms of being able to store backpacks inside of backpacks for days. But containers sizes themselves will increase based on how full it is

Ideas:

• Small/thin items like most alchemy items or some swords/daggers will be stack-able to a limit.
• Filters:
  • Importance: Make it so you can mark items to be of different importance value, so if you are trying to put a item of high importance into a container with enough space of low importance items then it will prioritize the high importance item.
  • Opentop: Make some containers able to contain items that are slightly taller than the container, say a staff in a backpack.
  • Special slots: Allow some containers to have exclusive extra slots that can only be filled with item types it defines. These would not be separate containers and just have a straight item limit. So like, using the campfire backpack as an example, that backpacks exclusive slots would be torch and axe, and I think tent? I cant remember if the tent shows up.
• Magical containers that don't act as a grid, and can fit any item of any size so long as there are cells available.
  • Things like nipple/clit piercings, earrings, plugs. Maybe make them so that the more that is stored in them the harder or more frequent they vibrate.
• Make the vagina/ass usable containers that can increase in size if you train them. There will be a limit on item size that go into it. As funny as shoving a whole set of iron armor in would be. Plugs may be needed to keep items in there. 
  • falling or getting hit with potions inside you may break the potions and give you the effects. Imagine having like 10 lactacid in there and all of the popping. Let's not worry about that glass for not >.>
  • Putting unprotected alchemical ingredients in may cause them to be consumed. And maybe some of them have a different effect found when tasted a different way...   
• Make some clothing containers, for pockets and stuff.
• Make hands default containers. As you may not have clothing to use.  
• Special containers for alchemy items, weapons, armor: These containers will be able to fit the items they were designed for more efficiently.
• Ergonomics: The better a containers ergonomics, the more weight it reduces.
• Press a key to drop heaviest containers to get below carry weight. 
• I was thinking about some type of sled container that could follow the player. Making this is out of my experience right now though. I like the idea though.
• Container material: Material can increase the amount slots available. A rigid material will be only what is described. While a stretchy material can be stretched.
• container durability: As durability drops the amount of items it can hold lowers slightly depending on the material. 
• Hardcore options:
  • Potions/ingredients need protection when in a container with other objects. So potions would need linen wrap or some such thing.
  • Having to sort a container will take time.
  • Dropping a bag will take time depending on a complexity stat: So a backpack is easy, a belt mounted bag may be harder. Dropping bag may damage items.
  • Weight related speed/stamina changes: Lower the maximum carry weight, as you get closer to the max you start to consume stamina. While at 0 stamina you will be considered overweight. When you are over the maximum you begin to slow down, having no stamina means you collapse. Potential to pass out. If you pass out youu may damage items.

So that's it for the containers themselves. But with the containers I was thinking of a companion mod for economy changes to compliment the limited inventory and to make the grind for hardcore weight mechanics worth it.

Economy ideas: 

• Add material quality to items, the higher the grade, the better price you'll get. This would be for most goods, alchemy items, armor, ore(Can ore be bad quality before being refined?), etc.
• Add the ability to sell embalming tools/linen to tomb workers, prison guards.
• Add ability to hand over stormcloak/imperial items/body part over to the other side as proof of kill and get rewarded.
• Mercenaries don't require an up-front price, but will take a cut of selling profits when you need them to protect when you go outside.
• Increase base price of metal cups and plates.

I have other ideas on making skyrims economy more engaging without poorly impacting gameplay or making money too easy, but I'll make those in another pose as I plan on writing a few more entries on other ideas I have.