Well, I've read through a bunch of threads and haven't found anything explicit on this.

The threads I have read contain posts that only mention Delta Medallion gold and above can fly standby at all (but it is free for them) - what about Skyteam Gold and above (in my case, Northwest Worldperks)?

Delta's same-day confirmed option works for anyone, but costs $50 per passenger, correct?

Are companions of Gold / Plat elites allowed to fly standby also, or do they have some stupid policy that forces you to separate if you want to standby even if you are traveling on the same confirmation #?