Settings are only allowed in the Beyond the Manual section. A number of people have shared their settings there. You can find those with a search:
https://community.glowforge.com/search?q=cedar%20settings%20%23beyond-the-manual
Also note that wood is not consistent even within varieties. So, there is really no substitute for doing your own testing.
Yes. The surface you are engraving has to be between the surface of where the crumb tray would be and no more than half an inch. So, to engrave on material an inch thick, you would have to remove the crumb tray and, prop the material so that the surface falls within that range. There is a lot of discussion about ways to do that in other threads but, that’s the basic idea: get the surface above where the tray surface would be but, below half an inch, use set focus.