Nice, I have NetBSD v10.0 on my Thinkpad T420, and issues I had with an external monitor has been fixed plus is is more zippy.
The only remaining issue I have with 10.0 is when the system is under very heavy load, Xorg can get temporarily corrupted after about 1 hour of the job running. I create PR 58217 for that issue.
In reality, I think very few people will ever run into this problem, but hoping for a 10.x fix some day :)
No, to write to a CD, you need to use specialized software, not just a simple copy.
Plus what about copying to replaced a files already on the CD ? I believe you need to clear it first then rewrite everything back. CD are about as inconvenient as a media can get.