Sorry for the necro, but in looking at these questions over the past few days, THIS THREAD looks like it has all of the heavy-hitters in it, and probably, the most respectful discussion...
Disclaimer: I thought I'd do some research, and ask my question in an existing thread rather than open a brand new one. This way, we're not opening a new can-o-worms, and adding to the number of threads on the same subject. Apologies to those who are thinking, "OH GOD, NOT THIS AGAIN, but here's the disclaimer. Yeah, I went there. Abandon all hope, ye who enter here.

So, I'll get to the questions at hand:
It's been mentioned above that Clay Cowgill doesn't use MAME to run emulated games, and that the boards he sells (ArcadeSD, I believe? Confirmation respectfully requested!) do NOT come with ROMs, and this is in an attempt to keep them 'legal'. Is it fair to say that, because he has built his own emulation software, and builds a 'for profit' solution, that it
is, in fact, legal?
One step further. Let's say I own an actual arcade board - let's say Galaga - and have the ability to pull the proper chips and download the ROMs from it, install them on an SD card, and run them on the above mentioned hardware, would
this be considered legal?
Here's my over-arching thought. If the answers to the two questions on legality both point to "yes", what would stop someone from amassing a huge pile of working, classic arcade PCBs, backing them up and using them in an ArcadeSD board in
whatever environment they choose? (I'm in Canada, and in speaking with the CRA - our Tax Agency - I understand that we would only pay tax on the profits from an actual paid arcade machine, and not some weird "you have an arcade machine! woop! woop!" tax I've heard about in different parts of the globe.)