Nice writeup!
I managed to finally get a gen setup recently. The KEY was the interlock! I have a manufactured home, which means I have a main panel that's outside the house. I needed to be able to power more than just the house. Key is the pump house. Now I've got a garage (have had a shed too), and this is served by the main panel. Everything from this panel can be run from the generator now.
It was a couple years back that I'd picked up my generator, a 1993 Onan/Cummins 7.5kW (DKD), with a Kubota diesel. I have on-site storage of diesel fuel, so generally I have ample fuel. And I'm a diesel guy
Wasn't until I got my garage built that I was able to tie everything together: generator sits on a concrete slab next to the garage and plugs into a box off the side of the garage- the box goes into conduit that runs away from the garage and over to the service panel.
Be sure that if you are going to run your generator back-feeding your panel that you un-bond the neutral (referred to as "floating neutral"). The neutral needs to go from the generator head to your panel and NOT tie into any ground on the generator.
This is important as there should only be ONE neutral path (and that will be at the panel): a proper neutral path is what can save your life. When set up this way the generator should NOT be used as a standalone generator: I removed the outlet boxes off my generator so that there's no way someone could use it standalone (still need to label it such). Check with your equipment manufacturer (info, or call): could be a simple jumper or rewire; could be that it can't be done- ground and neutral are tied in the generator head?
For figuring when power is restored, I'll know by seeing lights come on at the neighbors.