Anybody is here? All another users have same letter size and nice readability?

Linux Mint 18 Sarah, Kernel 4.4. Default fonts

Hello. Opera's fonts have different letter sizes in text on many sites. Other chromium browsers like Vivaldi are ok with that (the same default fonts are in settings). I don't like to move on Vivaldi only because of this problem.

The repository 'https://deb.opera.com/opera-stable stable Release' does not have a Release file.Data from such a repository can't be authenticated and is therefore potentially dangerous to use.See apt-secure(8) manpage for repository creation and user configuration details.Failed to fetch https://deb.opera.com/opera-stable/dists/stable/non-free/binary-amd64/Packages 404 Not Found

Опера пошла по пути чертого хрома, теперь дизайн такой же, заметки, блокировщик рекламы вырезали, настроек нифига нет - как добавить кнопки и панели? Еще и каждое окно - отдельный процесс. Что за убожество.