> EU membership means rule from Brussels.

This was the Brexit lie, and it's not really a sustainable argument post-Brexit.

> Joining can take years, in the meantime it would require severe austerity measures to stabilize the new state's finances.

A referendum wouldn't require leaving immediately; again, see Brexit. Negotiate an EU entrance while preparing for exit.

> The SNP has never resolved many of the open issues that caused them to lose last time.

Again, didn't stop Brexit.