Dynloth

Hi. I miss an option here that would show unanswered content (topics with no reply).

It isn't in the ACP but on your FTP - conf_global.php file.

I understand the design is made up of rows, and some of the stuff like "follow this content" is probably a global row that gets added across all types of content. And then you have to have a "responsive" design thanks to Google's mandates, which makes it more complicated. So I understand it can never be "perfect".
Still, I think for the most commonly viewed parts of the forum, having three inches of white space below the forum title, something needs to be done about that.
The only reason I am pointing this out is because we are moving away from our heavily customized skin in order to make updates easier, and because the default IPB skin is now good enough that I feel it's okay to use. (We just replaced the header and footer with out own.)
Ideally, this is what it should look like:

That's not currently possible. Likely in the future but not ETA yet.

I don't think this is related to this application, and I assume you get the same error if you try to install anything else.
You'll need to submit a support ticket to IPS about this.