I would suggest adding the following improvements:

1. Add the ability to create categories for feeds. Currently, it's Top 50 or My Sources. I like to categorize my feeds.
2. Remove already read feeds and add a button to mark as read, mark all as read.

That's all for now... I would like to ditch Feedly and I'm thinking that it may be possible (at least for me) by having Opera sync my RSS feeds between PC and phone.

I tried the reading view in Microsoft Edge and was pleasantly surprised by it... There are some extensions for this but none of them work nicely, at least the few I tested. I tried to like Instapaper and while it's nice, I can't be bothered to go to a separate service to read stuff from the web. So, +1 on the built-in reader mode for Opera.

I think it would be nice... I don't use Skype that much, but it would be nice to have the option.

Yes... I was pleasantly surprised by Edge's reader mode. I'm not going back to Edge just for the reader mode, but this would make a nice addition.

I'd say add a scroll button to go left or right once the tab width is below a certain length. Seems like an oversight to shrink tab size until its almost unusable.

Just providing the option to hold down Ctrl and selecting multiple tabs would go a long way...

I think this would be nice... maybe not with Shift as this actually closes the tabs, but Ctrl seems more intuitive.

Just recently I had an unresponsive tab, that eventually led to me force-closing Opera using the Windows Task Manager. As a long time Chrome user, I thought I could force-close the unresponsive tab by using something like Chrome's Task Manager. I couldn't find it myself and after a cursory Google search, I found the Shift+Esc keyboard shortcut. Maybe place a shortcut to it on the "more tools" section or as a menu option when right-clicking the tab bar?

Yep... would like to see this.

I would like to see that... may make me not use the Spotify app at all!

So, I tried the Spotify Web Player and it kept giving me an error message and prompting to reload. I came across a post on this forum with the same issue. So, disabling Opera Turbo did the trick... I noticed Opera Turbo is an all or nothing approach. Maybe have an exceptions feature for Opera Turbo, so sites that aren't compatible (for whatever reason) may load correctly.

I tried the reading view in Microsoft Edge and was pleasantly surprised by it... There are some extensions for this but none of them work nicely, at least the few I tested. I tried to like Instapaper and while it's nice, I can't be bothered to go to a separate service to read stuff from the web. So, +1 on the built-in reader mode for Opera.