Hi, Benjamin! Thanks!

There was also DC update last week Paul mentioned about new button in WYSIWYG editor. 

You can click upload button (red circle in a screenshot) and image will be uploaded to your message in the place of cursor.

Of course it is good to stretch it to 600px - you can do it if you select all the image and click image button (red rectangle in screenshot) and set image's widh.

I did it to the screenshot of the post.

Hi, Mike!

Nice to see you in InterSystems Developer Community!

I have you book on my table) Thank you for your work! Can we wait for any new books from you?

I see Paul and Benjamin answered your questions. 

Here are my 2 cents: COS highlighting,  small FAQ. But as Paul mentioned DC is changing weekly so some of the advices became obvious some has become deprecated already.