Like your list and think it's pretty dead on. #3 will cause more adoption naturally and increase retention. Currently this feels like being on Myspace having to be at my computer to post. 99% of my facebook time is on my cell, very rare I use my computer for it.
And #1 is Top of my list. My feed gets cluttered with resteems and has caused me to unfollow a few people that resteem everything under the sun vs quality, but I like their posts. Being able to toggle that on and off would be a huge help to make sure I don't miss content from those I want to read in my limited time. If there is more time then seeing content from others is of interest and then it makes sense to turn on the resteems...but I should be in control of this.
I created a front end called steemfeed.social that allows you to filter out resteems (among a host of other things). It's still pretty beta at the moment, but it's there if you want to see only the original content of the people you follow.
I am with you on this @thedarkhorse and have never seen anyone mention it. I too quit following some folks that like to resteem so many posts.
I like their posts but would prefer not to get so many in my feed they resteem.