I’m not sure there is one easy answer to your questions, although if you explore the Designing for Laser topic in the Glowforge Tips and Tricks category it should help.
If you have a file that you would like to be checked out to see if you are on the right track, I would be happy to try uploading it to the GFUI and do a critique on it to see where it might need changes. Just upload your SVG here (or send it to me in a private message if you prefer).