I think I had a lot more respect for the people running Boonex before this post. So let me get this straight: Boonex Dolphin is an "open source" application intended to encourage outside contributions and the company that provides paid supported versions is saying "we don't like your solutions to making dolphin usable on a non-desktop screen, we want to make a watered down, chiclet button interface that looks the same on a 4 inch, 320x480 smartphone screen, used by a guy with big see more fat fingers, as it does on a 30 inch, 4k monitor used by someone with a mouse? Someone using a flexible wrist display or one embedded in glasses? Finger, pointer or voice input? Why be limited to a one size fits all solution?

I don't know about you but I find that a site that adapts to my smart phone is far less disconcerting than having to pinch, scroll and unpinch to get anything basic done navigating a non-responsive website and I'll wager that if the mobile browser had come first, screens that are 4 or 5 inches at best, there is no way we would be looking at web pages that look like what the boonex.com website currently looks like when viewed on an iphone. Could you imagine if there was a rule that all printed material had to use the exact same font and be designed the same--same number of columns, same numbers of words across a column, and same number of lines on a page, regardless of the size of the printed material or its intended audience? What good does that do anybody? I've got three recommendations:

1) Don't kill the valuable work that people attempting to come up with solutions to this issue are doing by not supporting their efforts. Recognize that their attempts are potentially thwarted by an implementation that could not forsee the explosion of cheap, portable, universally connected computers that we call smartphones or their big cousins, tablets.

2) Before you get the boonex environment to work on smaller/bigger screens. Get the dolphin administration functionality, or at least most of it, to work. Go to demo.boonex.com with an iphone and try to log in with an administrative account. Here are the problems I run into:
a) login popup is not pinch friendly. It slides off the screen before it gets to a size where I can read the characters and submit button.
b) the member menu is not pinch friendly. By default the items on it are far too small for even my little finger to click on, but when pinched to enlarge, the whole right side of the menu disappears.
c) page builder functionality doesn't work or at least, I can't figure out how to move, add or delete blocks from a page with my iphone. I can't tell you how frustrating it has been trying to convice my business user that I can't make a simple change because I only have access to an iphone or ipad at the moment. Get things set up so that you feel comfortable managing a boonex site from a phone or tablet and I think you will learn a lot in the process.

3) It might be better to talk about the pros and cons of each of the four approaches you have outlined. I really don't think there is one universal, single solution that is best in all cases. For example, apps are good for the reasons you stated but an Apple app is a non-starter for anyone with a business or content that Apple will not approve for the App Store. Another problem with the Boonex Mobile Apps is that they don't support some of the core Dolphin functionality, like Events, Forums, Groups, Timeline/Wall, etc. Responsive design might simply be hard to make work reliably or lack standards for implementation but I would take it in a heartbeat over any of the other options because I know that it would provide the best experience for our users. A more functional app would be a close second. A Universal UI might be okay on a phone or TV but becomes limiting for other devices. But on the other hand a UUI doesn't prevent someone from implementing a responsive design around it, so what is it really? Universial UI or Responsive?