Questions on bags

I have a belt pouch (F6) that can hold 5 items and a bag (F7) that has been upgraded to be able to hold 10 items.

Now,

-Where can I find the 3rd bag that my that my Inventory screen says I could have (F8)?
-How much space will it hold at start and can it be expended? If so to how many items will it eventually hold?
-Can the belt pouch be upgraded to hold more then 5 itmes?
-Can my actual bag (F7) be ugraded even further, or is 10 objects the max it can hold?

Thanks alot.

Belt pouch stays at 5. You can buy bags and then runes of holding to increase them from 5 spaces to 10 spaces max. Also, there are certain collectors who will give you a bag for certain items. It is easier to just buy them though.

Same place you found the 2nd

Same as the 2nd

Nope

10's the max

Thanks a lot, guys.