Yes, a lot of good and interesting points. I, for one, vote against the bloodstains.... I rather enjoy butchering animals on my bed.. thank you!
Turning milk into butter and cheese i believe is possible now with the modding system. Although, someone with more knowledge of the intricacies of modding would have to verify that. Pretty sure it's possible though....
I think animal husbandry in general would be a great addition. But, for me, most interesting is the thought of catching wild birds and taming them. Currently, you can find bird nests with eggs, so maybe it would be possible to have a steady supply of eggs from tamed birds (and feathers for arrows?).
Then once eggs are a steady part of ones diet we need scrambled eggs with сала / bacon!! Yum!