David, What a great number of questions! It seems there are many variables involved. Professional respect, ethics, as well as a keen business sense and the lack of' can all be taken into account. I once visited a friend and older tattooer in the Modesto Ca. area, He has been there for years, and I mean years. As we were walking to get some dinner up the street I noticed another shop just across the way. they had just opened a few months prior to my visit. My friend had said to me, 'They never even came by to say hello'. we quickly dropped the subject and continued on our way.
First come' first served', on a location is my opinion. If one is looking to relocate or open a shop One should investigate who else is in a close proximity, take in account a respect for that persons shop and that they were there before them. If it were me, I would honor my decision on my current location, hold on to it, and renegotiate the lease, with the help of a good lawyer. Through this, continue to investigate alternatives without making any rash decisions. You seem like you have everything under control, great Questions!! cant wait to hear from others about this.