With regards to the lead thing- why don't you use a chain lead?
And teach him a good heel (clicker train/positive reinforcement).

The barking when you return sounds like over excitement, although it is very difficult to say without seeing it "in the flesh". If it is over-excitement, I would be enclined to totally ignore him until he calms down.

You mentioned speaking to a behaviourist. Whereabouts are you based? Someone might be able to recommend one.

A few questions:
What is he fed on?
How often is he walked?

What is he walked on? Just collar and lead?

Hope this helps x

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