it's fine, dude. Don't sweat the small stuff. Pick a few exercises, pick rep ranges, and get stronger on those exercises in those rep ranges. Doesn't matter if it's bars, dumbbells, machines, the smith, whatever.
Your stabilising muscles will be just fine, and it's a way better alternative to not being able to challenge yourself.
EDIT: and it's clear you're doing a lot of reading on the subject, which is great, but make sure you are doing practical research of your own. Just because you read somewhere the smith is bad, doesn't mean you shouldn't try it and form your own conclusions.