Same here.

I just hope the landscape is not "forced" in the tablet like portrait is now on the phone. Landscape does not interest me that much, since I hardly ever use any phones or tablets in landscape (photos/videos don't count). However, those rare times that I do I feel landscape should be fully supported, too. The split screen feature may change my views about landscape use but that shall be seen later.

This probably bothers me the most. The sliding has been an innovative feature and I would have loved to see the possibility to also up/down slide for more functions, but even if not, 2 is way more useful than one.
The covers + their sliding functions have also often been the most impressing feature while showing the phone use to others.

What I don't really get is how come horizontal swiping is supposed to be such a big problem that it is not possible to keep the sliding action in covers? The way I use the actions even now is hold&slide anyway, not plain swipe like one does while changing views.
(There is also the relatively wide gap between the cover rows that maybe could've been an option to use as the "swipe area" even though not the best idea, I'm sure).

Exactly. Also the new aim&tap for a function is really a big step back from the relaxed cover slide with much bigger area. And I hate it.

This would've been a more preferable choice to the single tap.
Also, there would've been certain appealing symmetry (to me anyway) that when in portrait, slide the covers left/right and when in landscape, slide up/down.

I totally share this hope with you. Speaking of covers, the functionality is already in my muscle memory so I'd hate to start learning to aim & tap instead.