We've built a number of sites in webflow, some big and some small. We're more than thrilled with the experience thus far and have loved every second of it. Webflow is awesome and I can't wait to see what new features are up your sleeve.
Off the top of my head, I've put together a list of some things I can think of that would help an organization use webflow more efficiently. Even without these features, we've been able to integrate webflow into many of our processes and will continue to do so. Admittedly, I didn't research each of these topics, this has just been our experience thus far.
1) Ability to upload a site that was exported out of webflow back into webflow
We have some designers who are now able to work on pieces of sites, but they can only take it so far and the sites have to eventually wind up in a developers hands before launching. Once that happens, the site is forever locked out of the webflow environment. Or, simply a live CSS/HTML viewer would be helpful while working in design mode. "Markup Mode, Code Mode, Skeleton Mode, whatever" Include a warning that altering code may break stuff.. You guys have version control and sites can be reverted if someone messes up.
2) Customizable media query's
I've seen this mentioned before, and sometimes it can be an issue. Desktop/Tablet/Phone view is helpful and works 90% of the time, but I have seen the responsive layouts change between media query's, and if you're not manually scaling the browser, that can really bite you when you eventually do check it.
See this article: http://webdesign.tutsplus.com/articles/life-beyond-960px-designing-for-large-screens--webdesign-7348
3) UI customizations
For example- maybe nested elements could have customizable thicknesses or alternative colors of borders: Sections are light blue and thin, containers are dark blue and thick, columns are orange and dashed, text is red and if it has span make it thick. I'm not saying it would be pretty, but it takes it a step beyond x-ray mode.
I think we've got 30+ websites that have been published/started/abandoned, with no organization in the main menu. It can get a little confusing.
4) Styling backwards/mobile first
This would be incredible useful, especially if you're working on the mobile view and figure out a solution that would also translate to the desktop view.
5) Copying elements/styles between projects
We have a client where we do a lot of little sites for them with different layouts and designs, but it would be great to have some shared styles/elements as it's still the same company, where it's not appropriate to use a template. I could see this being an issue with paid templates as people could exploit that somehow, but you can figure out how to prevent that I'm sure! Another cool feature here would be team level color palates/custom font selections or saved/shared image libraries for logos, etc.
Many of these relate to compatibility with old browsers
6) Browser warnings/will it work integration?
A lot of awesome features simply won't work in IE8, and I can only imagine how many sleepless nights have been spent by designers using webflow when their awesome site doesn't work in the clients IE8 browser and they don't care if Chrome is better. Unfortunately this is still an issue for many, but on the other hand, as Microsoft's support ends next year, I think many large corporations will abandon use.
7) Built in image compression prior to publish or upon upload
Jpegs, PNG's, etc.
Commenting in design mode (the way a developer comments code)
Test Mode/Fix it: I've seen some designers who don't quite understand how CSS works get into some major jams when designing something and they just end up "breaking" the layout. Elements extend beyond the body's width, background images zoom into the person in a photo's nostril when scaling down, things stop being responsive or not cascading down properly, etc.. What if webflow knew what was going on and with the touch of a button, you could see what's causing your layout to "break the rules"? In a production environment when there are deadlines and we're waiting to export code, someone without a background in development may not know how to fix something and someone might not be available to help them. This sounds bad, but it happens and the greatest benefit of webflow (in my opinion) is empowering those with major skills to expand into development.