I can help on the first part of your problem, as I ran into exactly this today trying on CTRLR in Windows 10, Cubase 9.
The solution to seeing the whole screen is to click on the menu option “Edit” then “Preferences”, in what you can see inside the windowed plugin on the bottom right.
From there, scroll down to the bottom. You’re in a form window called “Settings”, not “Preferences” because, well, I dunno. Maybe no-one noticed that before.
Where it says “Editor Bounds” change that from whatever it says (mine always starts up with 560 220 800 600 and I have no idea why) to 0 0 1024 768
The numbers refer to the relative position of your editor inside the VST plugin window. Leave the first two as “0 0” – that will always be top left – and change the last two to suit your plugin. 1024 is the width and that may need to be a little bigger, 768 is the height. You will need to close the VST Ctrlr window and reopen to see the changes.
Hope that helps a little?