Artboard resolution issues (Photoshop)

[Red Point]

ISSUES 1:
I have an artboard set to 1920 x 1280 px (at 72 dpi - 8 bit - RGB) - one among multiple artboards on my canvas. Whenever I create a new layer in my artboard, it sets the size of the layer to 3302 x 2753 instead of 1920 x 1280. No idea why Photoshop it is doing that. I tried rasterizing the layer, trimming it. Nothing seems to work.

I have read on the forums that many people complain about buggy behaviour when using multiple artboards on canvas (and this supposedly since years) and that there are serious usuability issues in regards to artboards (in Photoshop). I haven't used them until now, but my experience so far has been really bad. 

Is this a bug or a settings issue?

ISSUE2: 
In Illustrator, I can add comments to my canvas, expecially useful if I want to add my own custom description or title above an artboard. Trying that in Photoshop was a nightmare and doesnt seem possible. Any ideas on a workaround? Also up for discussion, will Adobe ever strive to create a common user experience across apps? Because right now its really bad.  

Any help appreciated.

*** Please do not post any lengthy explanations, just very specific help action items on how to solve this really anoying Photoshop behavious (= issue #1). Thanks. *** 

[Stephen_A_Marsh]

Issue #1: I believe that filling a new empty layer will create the fill at the bounds of all artboard canvas width and height plus space between canvas combined.

[Red Point]

Thank you Stephen, I just realized that. I wonder why Adobe did it that way, Tthey must have had a reason. But it is confusing. We now have 4 sizes (canvas, artboard, layer actual size, layer extended size). Not sure why they would do it that way. They must have had a reason?!?

Good news, when exporting the layer it seems to keep the correct size.

I did run across a third issue. When working with multiple artboards, one will run out of layer coloring options very quickly. Not sure why in the age of 16,7 Mio colors, Adobe restricts the use of 6 colors plus grey for layers. Grey?!?!  Especially since you can custom color code guides, where color coding is not at all important (at least less important than layer color coding), not sure why they dont give us more options here. I did up feature request. 

[Red Point]

You can upvote more options for color coding layers here: https://community.adobe.com/t5/photoshop-ecosystem-ideas/p-add-custom-colors-for-colour-coding-layer...(upvoting window at the top right)

[Stephen_A_Marsh]

When artboards were implemented, they were based on layer groups. Photoshop can only have one canvas. Artboards appear to act like a special layer group mask, providing the appearance of a separate canvas.