-I've been wondering if the next add-on would give wandering trading caravans moving around with guards, like there would be caravan at stables in front of Riften stables with mercenaries loading it. Depending on how wealthy the trade is, having more or less mercenaries.
-Also random bandit camps not shown on map, raiding everything that goes by with having only few tents and a campfire.
-There also should be adventure companies, killing and looting stuff all around. Seems kinda dull that u'r the only one exploring such a vast world, i'd like to assassinate those adventurers and raid the caravans or join with the adventurers or help out the caravans getting rid of any threat for some gold.
-There should housing around the cities with a few farms and poor beggars which might attack you in the hope of gold and food.
-I would personally like a lot if there was more finishing moves for sneak attacks and power attacks, stabbing the back, hitting a dagger in the neck or under armpit to lungs. Having the chance to crush a skull with warhammer or chopping hand off with greatsword
-Would also be fun to spot more thieves while going looting some houses just to trike him from the shadows and steal everything :>

There is more, but these i'd personally wish to see first since i don't know how to use the toolkit or any other softwares like that :/