Workspace switching with and without window is as you mention. Drag to left/right too. With 3.26 you can also drag the left/right split to arbitrary positions that may be more beneficial to the task at hand.
GNOME uses Super (Windows) by default instead of Alt for drag/resize. You can change it (and lots of other stuff) in the Tweaks application.
Resize uses secondary click instead of middle I think, but also available in Tweaks.
For what it's worth, you can have all this in Plasma 5:
* The "Switch to adjacent workspace" and "Move Window to adjacent workspace" actions are not bound to shortcuts by default, but you can do so via System Settings > Shortcuts > Global Shortcuts > KWin.
* Alt+Left and Alt+Right for drag and resize, but can be configured to be the same as in Unity in System Settings > Window Management > Window Behavior > Window Actions.
* Quick-tiling (full, half, quarter) is enabled by default.
My main app-switching feature across machines, OSes an desktop environments has been Super+[1-9] to focus my pinned app number [1-9] on the taskbar.
This works in Windows. It worked in Unity. It works with my custom i3/sway setup.
I never quite got it working in Gnome/KDE though.
This single key-combo is super-crucial to my flow, and if Canonical has shipped a default-config which preserves this behaviour from Unity, I'd be super happy to give it a spin.
That's a terrible restriction for people who have many virtual desktops. I've used 10 in two rows for years (or 9 in xmonad) so that's my mental model of where everything is located.
* Ctrl + Alt + left/right/up/down to switch workspaces
* Ctrl + Alt + Shift + left/right/up/down to move the current window to a different workspace
* Alt + Left mouse button to drag windows
* Alt + Middle mouse button to resize windows
* Drag a window to the left or right edge to resize it to that half of the screen.
No idea how much of this is Gnome/remains in 17.10. Or how easy it is to set up. I guess I need to give it a try.