Hello! Viewport visibility is a bit different on 2.8x. There are two kinds of toggles now, global (display icon) and current view only (eye icon), so the first thing you want to do is enable both to be able to check the visibility of your objects.
To choose which toggles display in the 2.8+ outliner click on the filter icon. Once enabled check the visibility of missing objects.
(ignore the arrow on the camera toggle, I borrowed this screenshot from another answer of mine)
Regarding the shortcut, there was a change in 2.8x and the keys involved in viewport visibility might be included in this. I advise you to check the new keymap and adapt it to your needs. It can be found in
Edit > Preferences > Keymap.
Units are directly linked to each file. They can be changed in
Scene Properties > Units.
To make it a bit more “default” you can edit it in your startup file. Create new file (Ctrl+N), change the unit then save it (Ctrl+U). From now on all projects created using the startup file will have the desired unit.