• What are the odds in the UK, that Scotland will pull out of the UK to rejoin the EU?
• More to the point, what are the time frames of that two step process?

It depends on how badly things go (as if they're not bad enough). Scotland is currently governed by the SNP which has always campaigned for independence. I reckon that if there's anything but a soft exit from the EU, they will call another referendum on independence (the last was 55% stay) and get it. Maybe in 2 years?

Difficult to say, time will tell.