I’ve been using Runbox for a couple of years and agree the web interface is lacking. There were also multiple significant server outages last year, but it has been much more reliable this year. As long as you don’t use the webmail often, Runbox is a good affordable email provider and is great for families due to the low cost of sub accounts (additional users).
Codecs are a legal grey area that many distros are choosing to include out of convenience since there has not been a problem before. Since Fedora is associated with Red Hat/IBM which have a lot of money and are bigger targets for lawsuits, they are choosing to play it safe by not officially supporting many codecs. It is the same with openSUSE.