The problem with tabs is the same as with expanding: You have to find the tab and click it every time you want to look at the description/comments/art. If description/comments is under, all you have to do is scroll your mouse up and down, it couldn't be any simpler and more convenient than that.

As for "jerks posting long strings" no, this is not how you solve that. You solve that by not writing shitty code. FA's comment section is screwed up because the coding is horrible, and not because of the layout.

+1 for separation. I know the current design trend is "clean as fuck", with often nothing but white space playing the role of separator, but honestly, that is counterintuitive. It ma look trendy, but sure as hell makes it harder to see what belongs where. Design should never be more important than usability - but then, that is exactly why we ask for comments and descriptions under artwork. :P

+1 for comment nesting and tree lines too. Mentioning serves a different purpose IMO, and the more comments and more replies, the harder it becomes to see what belongs where. Again, just look at FA, huge comment trees are common in this community.

"the 1000 character limit for comments should be removed. Splitting longer comments into several smaller ones is not only annoying, but also clutters the comment section up"
^ This

"I'm not familiar enough with the matter to present a solution for the implementation of those ideas for mobile devices"
- Generally, for a mobile layout you want to move everything under each other anyway, since mobile screens are tall but narrow. So moving comments and descriptions under artwork will actually be in tune with mobile friendliness.

Addendum: as far as "make it bigger", once they are moved below the artwork, you can add controls to collapse (and expand) the comments and description sections separately, if you don't need them. Default we start with the artwork occupying most of the screen space, then, we can leave it at that, or, if we are interested, we can scroll down for descriptions and comments.

Collapsing description can be useful if it has a large description, and we just want to see the comments. Because of this, I would place the collapse button on the top of the descr box so as I scroll down I can collapse before having to scroll through it at which point collapsing wouldn't achieve much anyway.

I would prefer a permanent layout change to move both comments and descriptions (the latter is the more important) somewhere they have space - and to do that without taking space away from the artwork, moving under is perfect as you can scroll down as much as needed while the width of your screen is limited (and side-scrolling is obviously not a vaild option). Yes, most people have wide sreens nowadays, but it still is limited, while vertical scrolling is practically infinite.

The problem with the "make bigger" route IMO is that it offers a choice between two evils: Make this bigger, but let something else suffer, or the other way around - what if I want to pay attention to everything? With comments and descriptions below, everything always has plenty of space and all you have to do is scroll, which is the easiest form of navigation, instead of locating and clicking a button every time you want to switch between reading comments and for ex looking at the artwork.

Either way, using something that does not work in all major browsers is not generally wise - unless you don't care about your users6audience and want to go a "take it or fuck off" route.

I don't need a toolbar that makes it easier to insert very limited and unintuitive formatting. I want the option to use less limited and more intuitive formatting.

So if I want to quote my favorite poem that inspired me I shouldn't quote the full poem because that's bad practice?

If I quote from an article something relevant/important and it's longer than a few line, is that bad practice?

Come on... try think out of the box! Quoting someone you reply to is NOT the only use of a quote!!! In fact, it is only one of lots of uses.

When a submission has 200 comments, good luck reading that in a tiny narrow column on the side of your screen with a football field size of empty, unused space taking up most of the screen as you scroll down.

+1
I'm not a character, I'm me! :(

Absolutely yes! +99999