I'm going to answer piecemeal and out of order.
I thought that it was a requirement that international post be sent Air mail, but I can’t find anywhere that actually says that.
I'll see if I can figure out what happened to that portion. I can't remember if we moved it or removed it when we updated the rules.
Do I have a swap spot taken up for 6 months because of sea mail, even though I've sent and my parcel has been received?
No. When and whether or not you receive a package has no bearing on your own feedback.
Do I have to wait the “up to 6 months” to get my swap spot back?
Not at all. I hope no one told you that.
And considering that I’ve not technically finished my end of the swap process by posting photos of what I’ve received, am I even aloud to ask for my swap spot back?
Posting photos is not a required part of swapping on Craftster.
Is it a case that I just wait 6 months before I put my hand up that the parcel may be missing? (I live in Australia and have had a swap parcel from Canada that took 5 or 6 months, the pop tarts that were in the parcel had gone out of date and were nothing more than crumbs by the time I got them. That parcel was considered missing after 4 weeks)
How long should I wait for this parcel before it’s considered lost?
Do I give it 7 months just to be sure?
What if my swap organiser or partner are no longer on Craftster?
Should I just consider this swap a bust and move on?
I would open up a Help Desk ticket about these.