1. Somewhere on your status telling you what Stone is currently active. (ie one of the 13 stones a player activates)
2. Somewhere in your status telling you if your diseased and what kind of disease it is
As others said, look at your Active Effects menu.
3. Instead of having 1 companion, 2 ( other than the dog) I wouldnt mind a wizard and an archer to join my warrior
Summons can give you multiple followers. You can also start a couple of quests that give you a follower and still keep your current follower. As long as you don't finish the quest, you keep both followers.
4. A manequin to put our armor on? Like there is a weapon rack for weapons.
They have these. Buy the home in Riften.
5. The ability for the dead corpses to disappear after a few days? So many are left behind...
Again, this is in the game. Large corpses, like dragons, disappear as soon as you leave the area. Bodies from other NPCs will disappear after 3-4 days when things reset.
Grand Tricker: There is fishing. But since you are Dovahkien, you have to fish with your bare hands! (Yes, I am serious. Go into the water, look at a fish; you can "harvest" it with the activate button)
Companion weight allowance (haven't found it if's there)
All companions have a 200 carrying capacity.
I am laughing out loud with all the people who want to add things that are already in the game.