Significant portions of the Glowforge unit’s industrial design were created in Rhino, and our CTO and cofounder agrees with your request. 
I suspect the reason for the different engrave depth was that one wound up as a bitmap and one wound up as a vector, although other explanations are possible.
Dear heavenly father, I feel like I just sat through an advanced mandarin speaking class and I’ve only ever had kindergarten ABC’s in English. How do you learn all this? I’ve had this machine one week and it’s been sitting here one week, and I have not the first clue I don’t understand any of what you all just talked about at all I’m in trouble, I have a note that my husband wrote me that I would like to engrave on a piece of wood and maybe possibly make a frame around it with some braided trim that I saw in the Glowforge premium files. I have no idea where to start and I’ve ordered some of the vinyl from Glowforge because I’ve been asked to do vinyl on carrying bags for a quilt field and I have no idea where to start so I guess I should start praying and reading can’t even get ink scapes to load on my MacBook Pro Something about safari extension preferences? Holy cow.
You probably want to start with something like Inkscape. Rhino is not necessary to design things for laser cutting. Most of us don’t use it at all.
Be patient with yourself. Take it a little at a time. The Logos by Nick YouTube channel has some great tutorials. Here’s a good Inkscape intro:
There is a Glowforge palette for Inkscape that lets you separate operations: [edited]
For general Glowforge basics, there is a great starter resource here:
Do the little projects in getting started then follow @evermorian advice.
When you have done these you won’t feel so gobsmacked and we’ll be able to give more direct help.