Please, the next version of ZorinOS, could have its look / interface based on QT (KDE), in addition to a more beautiful look, it would be much more stable and with a much better performance due to Kwin.
The app launcher (start menu) should lose that talk bubble border and have only circular borders.
That makes no sense. That would no longer be Zorin OS. There are plenty of distributions that rely on QT (KDE).
You can also install KDE in Zorin anyway, if you wanted to.
I think LXQt could be a viable alternative to xfce but it would take the menu back to a Win 2k look. 
Not KDE bro, only Qt and Kwin. Because is more stable and fast
@mathpfvr ooh! Not heard of KWin - do you have a link?
Ooh and forgot, LXQt doesn’t have to look like Win2k:
bro kwin is a window manager, present in KDE and DDE (deepin), as it is very stable and light, it would be excellent for zorinos to implement in its interface.
A lot more goes into making a distro than just the desktop environment. There are hundreds of back-end utilities and scripts that have to be manually integrated together to produce a smooth-running system -- THAT is what a distro does on your behalf. They select bits that work well, connect them together, and then put some nice decorations on the surface for you to look at. A lot of the work for Zorin is already done by Ubuntu developers, but Zorin is nonetheless more than just Ubuntu with a custom GNOME environment on top. You can replace the desktop environment and still benefit from the work the Zorin developers did to make Zorin work the way it does.
Personally I think switching to KDE would save them a bunch of time and effort, since KDE already does everything they put so much effort into making GNOME do. Switching to KDE would let the developers focus on under-the hood improvements exclusively.
I like that fat penguin, so cute! 
Well I finally managed to get Emmabuntus DE 3 installed again on an old drive. I discovered that Falkon browser only worked well in xfce - the video showing it breaking was I thought down to (upon discovery) switching to LXQt in live mode. However on install it broke there too! Artix, my current exploratory OS, is the first distro that doesn't have falkon browser break. Howeverl I have had a few system freezes and this is an old wobbly drive (if you catch my drift!). It does come with firefox and what I really like about Emmabuntus DE 3 is that it has MultiSystem USB creation tool included!