Right/left-click to select and the spacebar action can both be set on the first run of 2.8, or in the Keymap tab of the preferences.
Remove doubles can be done with Alt-M -> tap 'B'.
The 3D header (and any header in Blender) can be moved to the top or bottom: right-click the header, select "Flip to Top" or "Flip to Bottom".
In the Outliner, you can enable the "toggle selectable" button in the Filters popup. Click on the "Filter" icon, then click on the mouse cursor to enable the button. Now, you can click the cursor next to any object to make it unselectable, and it will remain visible in the outliner.
Collections can do everything Layers could do, and many more things besides.
Remove doubles can be done with Alt-M -> tap 'B'.
The 3D header (and any header in Blender) can be moved to the top or bottom: right-click the header, select "Flip to Top" or "Flip to Bottom".
In the Outliner, you can enable the "toggle selectable" button in the Filters popup. Click on the "Filter" icon, then click on the mouse cursor to enable the button. Now, you can click the cursor next to any object to make it unselectable, and it will remain visible in the outliner.
Collections can do everything Layers could do, and many more things besides.