Why would it be cutting your effective RAM in half? I know very little about hardware/software architecture and all that.

But going to hardwired will reduce the loss that comes with wifi. If you have already slow Internet, finding any way to maintain it without degradation can be worthwhile.

SSDs are not affected by magnets like a spinning disc. So, yes it is safe.

I would say, more than likely no. That being said, just try it and see. More than likely it’ll become apparent what is and isn’t usable (I’d guess the octoprint interface would become unbearable to navigate if you’re watching something at the same time).

You might also run into hangups on octoprint’s end, potentially halting prints, though I feel like that should be avoidable (I know I’ve had prints halt when my pi was undervolted)