Thanks so much for this extended review and your feedback and ideas, that helps us a lot!

• A night mode is planned eventually, but currently doesn't have the highest priority. It shouldn't be that difficult to implement where we use Material UI components/colours, but we will probably have to replace all the colours that are currently set by bootstrap classes with dynamic classes. Thanks for the suggestion though, that just reminded us to add it to the roadmap.
• We have a map as well actually, but it's quite basic at the moment https://travelfeed.io/map. A search function, clickable clusters, filter options, author- and location-maps are on the roadmap.
• We are not happy with the current editor ourselves. We want our users to have a modern "Medium-like" experience, but it actually is pretty hard to implement a really good WYSIWYG editor, since none of the existing solutions is perfect.. At an earlier pre-release version we were using https://editorjs.io/ which is pretty awesome, but it is a young project with a few severe bugs, so we decided to not use it (yet).
• Since the "Easy Editor", which currently is default for new posts, is a WYSIWYG editor, it would actually not need a preview. Would you still prefer a preview next to the post, or would seeing a preview before publishing the post (like on Medium) be enough?
• We are looking for a replacement for the markdown/html editor. So far, we like this one the most, and it has side-by-side preview. What do you think? https://harrychen0506.github.io/react-markdown-editor-lite/
• The 250 word minimum is a quality requirement, posts with less than 250 words don't appear on TravelFeed at all. This automatically filters out short and spammy posts in favour of higher-quality content, since, as you say, it is basically impossible to write a high-quality travel post with less than 250 words and users generally prefer not seeing these post at all.
• We don't offer Steem-specific options such as payout options to make our app easier for non-Steem users to understand. We think about offering these options as optional advanced/expert options in a future release, what do you think?
• We will add a "real" wallet as soon as we launch our token, the current wallet page basically only is a placeholder

We would love to see your TravelFeed posts about Nigeria! And if you have more ideas or would like to contribute to the development of TravelFeed, please don't hesitate to reach out to us!
~ @jpphotography, lead developer