I thought I’d create a papercut about this issue too when I found yours, regarding the space reservation in the outliner for the scrollbar.
I was the one patching the code to get that space for the vertical scrollbar.
https://developer.blender.org/D3650
Back then I’ve called for the space at the bottom too… but I’m too stupid to find it myself in the source where I need to be… Guess it needs a bit more than an offset here and there.
So yell there as well… 
You’re right. A better solution would be if we can reset just the UI arrangement to the startup file one, via a command, but that’s not a UI paper cut.
Proportional editing default should be connected. There’s little that this setting can’t do that the simple one can, so there are only a few occasions where “connected” is no good.
this thread is on fire! 
Visibility/selectability restrictions popover for Collections in 3D View allow for fast hiding all items with exception for the one that’s name was clicked. Brilliant, but there’s no easy and similar way to unhide all, despite the key shortcut. Maybe a double click could e used to bring back previous visibility setup? Objects visibility restriction popover should work the same way.
The content below was moved to appropriate topic: Left click select keymap
The left-click-select keymap lose grab’n’drag ability. LMB click’n’drag triggers Box Select no matter where or what is clicked. It should go like that:
To be consistent the first default collection should be called Collection 1 because when creating a new collection is called Collection 2 by default.
There is a bug reported last year, concerning the proportional editing connected not working properly in UV Editor, I don’t know how easy/hard it would be to fix it, but it might be part of a papercut.
As well as every object created for the first time could be named Cube.001, it is playing with my OCD haha 
Edit : Well not every object should named Cube.001 of course, but more something like [NAME].001, instead of just having [NAME] and then start counting.
I also think that in the default theme the facedots size should be 4 or 5 instead of 3 by default.
Make Remove Double Vertices operator available to all mesh selection mode context menus.
Removing doubles is a staple operator and a frequently used cleanup and optimization tool.
In pre 2.8 one could remove doubles from any selection mode, Vertex, Edge, or Face by accessing the W > Specials menu .
Currently in 2.8 we now have the new and improved W > Mesh Context Menu, but Remove Double Vertices is only available while in Vertex selection mode. While this makes sense from an organizational point of view, in day to day usage it is probably more of an annoyance, forcing you to needlessly switch modes for such a common task, when it works well regardless of selection mode.
I think this fits well here since it is probably just a simple UI change of adding the entry to the menus.
I agree. But only for files 2.79 and previous Blender version.
I like the idea of streamlining this common workflow, but I disagree that the per-material refraction should go away. Sometimes, you do want to limit which materials receive SS refraction, especially if the refraction isn’t looking the way you want and you just need the material to appear clear or transmissive.
Make camera navigation widget list cameras in scene.
This probably not as simple UI task. Instead of switching immediately, the camera navigation widget could be made more versatile by becoming a popover and listing all cameras in scene.
Currently active one could be highlighted clicking any other would set it as active one.
Very, very annoying, when trying to drag the black color slider, the cursor changes to Node resize mode, and resizes the node,…
I´d love to click on the black color handle and actually move the color handle.
Maybe a simple margin should solve this one!
I just use basic nodes setups and I’m not an expert, all the color selectors in the nodes and materials have an alpha input and I think that aren’t used, the difuse, the principle, emision etc. Will be better to remove that if it isn’t used .
Empty / Image / Transparency I think it should be Opacity, since with value 1 it is completely opaque, and zero is transparent.
If you name your collection “Collection 1” and save it as a startup file, it will start next time with “Collection 1” instead of “Collection”.
The Extrude function is composed of two functions, on the one hand it generates new faces and on the other hand it moves them. When performing Undo you need to perform two to completely reverse the action, otherwise the new faces do not disappear.
The Inset function is very similar, but it is executed in a single stroke.
I think both should work the same way, in my opinion executing only one action. Just as there are Rip vertices and extend, there should be Rip faces and extend (Alt + D) to duplicate the faces and keep them pasted.
