I'm confused by number 2, but it's a pretty good list.
1) YES I don't understand why this hasn't been addressed already. There appears to be no way to directly design 4k websites because of panel will not scale. 4k is beginning to explode in popularity and fluid design needs to be better addressed asap. Although I don't like the idea of modifying a div from the interface. I've seen this before in other web editors, and it gets clunky and can be buggy. I'd rather rely on the panel. If this ever became something a lot of people were interested in, I would much prefer this to be a toggleable option.
2) I don't think I get this point. When I want to "split" a container, I just copy and paste a div I want duplicated and add proper margin/padding/etc from there.
3) This sounds great in theory, but the problem is lines easily get in the way and can not only cause clutter, but create a more difficult time designing and force reliance on using a 'preview' and 'back to edit' shortcut or having to click the toggle icon at the top (this view seems buggy though so I never use it). I'm not sure how something disappears randomly. "Use Google Chrome" is my suggestion. But again, yeah a toggle button for this might be nice. It does get to a point though where you have too many things to toggle. The simplicity of Webflow we have right now is great.
4) YES; It's something I would expect to have made it into the final build. If you're going to notify me that I need a form just to add this element, you might as well add the form for me or maybe instead notify me that it is improper to add the element without a form but let me do so anyway. Either way works for me, but it seems ineffective to waste someone's time when they have to add a form just to add an input.
5) Yes, I would expect Webflow to have more elements to choose from in the future, and search boxes might be nice. Although if there is going to be a search box anywhere first, I would rather have it in the Style panel.
6) Then last option addresses the same thing for me here, although it would even be nice to have a search bar in the Navigator and when I select the element I am looking for everything becomes visible so I can see it on its hierarchy.
7) I'm not sure exactly where you're getting at here because Symbols and combo classes address this. BUT it would be nice if I could have combo classes for different elements with the same traits. If I have separate classes of "c1" and "c2" I should be able to have "style" affect BOTH of them. Not being able to do this adds lots of complications and it confuses me because this is something you can do with normal HTML/CSS and it's proper.
8) YES, I should be able to use Calc wherever I want.
9) Good luck convincing Webflow on anything in terms of pricing. They don't mind raising their prices too much and continue to not include simple capabilities like storing file types besides images and not being as transparent and co-operative as they think they are. Relying on third party options is more expensive and should never be a requirement for a web service like Webflow.
Many of my clients have chosen me to work with Wordpress and more popular: Squarespace. Both alternatives provide better storage options and more flexibility at a much lower cost. And for $12/mo, Squarespace provides unlimited storage of any file type with a limit of 20 pages (seriously, who needs more than 5 to 10 pages anymore?). Squarespace also integrates a free eCommerce platform with a reasonable 3% fee on transactions. AAANNND you get beautiful analytics which the client can easily see, which helps for the design process down the road. With Webflow, all of this is more of a pain and more expensive, especially as Webflow increases pricing. WEBFLOW, how about you become more personal and tell us how certain things are going? How are Interactions 2.0? I'm on the hype train but I'm beginning to get annoyed. It's really tough to stay positive when you're losing money on something you could have ignored or let develop on its own for years.
Did I mention that Squarespace offers UNLIMITED storage and blazing fast web hosting?