Couldn't agree more with your bullet point list!
I should add that if someone feels they are underselling themselves to their audience by sacrificing some level of art quality for an acceptable speed, then I have a trick I usually go by: Challenge yourself to make one impressive panel (or page, if the moment calls for it) for each 40 or so pages, where you go all out or nearly all out. But keep in mind that the more time you spend on it, the more you will have to compromise with simpler panels somewhere else to not kill your schedule.
This is a good way to remind your audience that you are damn good at what you do. Your actual target audience won't care about the occasional mistakes or simple panels. Their impression of you will generally be your last impressive panel, as long as it didn't happen 50+ pages ago so they forget it.
Sure, your haters will pick out the worst panels they can find, but their impression of you is already shit and it always will be. So ignore them. You have bills to pay and you can't let them get in the way!~
To pull an actual example, this is what I make when I have that occasional "Let's give the audience a kick in the butt and remind them I don't suck" day
Whereas this is a more average page:
It's not only a timesaver technique, either. It's a storytelling method. Big effort scenery and color work helps slow the reader down, forces them to think a little extra, and pulls them into your world. These are best accompanied with little text, because the picture tells the most. The quicker page is also quicker for the reader to comprehend, and allows more attention to go to the conversation or the actions at play.
More backgrounds and more detail aren't always the recipe for a better page. Sometimes they are a distraction. One of the comics I enjoy the most artistically often gets the reader response "it's pretty, but I didn't understand the story because it became too hard to read". In novels, too much description detail about things your audience is uninterested in will alienate and bore the reader. In comics, too much constant detail will lead the reader to look at your art only and forget the story is even a thing.