Help finishing steam boiler install

IsaacN

Hi everyone. I’m hoping for a little guide and help here. I’m converting from oil to gas. I passed inspections on my gas line and also new chimney liner... now that I have the gas inside, I am trying to finish my new boiler. I will post pics of the recent progress of the boiler. Hoping for someone to tell me what’s left in completion.
So, due to the way i had to come out the chimney to the damper, I had to cut some of the copper pipes...
question 1: boiler comes with a water cut off 24vdc but I have a hydrolevel water feeder vxt-120.. how do I go about wiring these two together, or do I need to get a vxt24.

Question 2: do I need a water expansion tank?

Question 3: from the pics, is there anything else missing that you notice, to finish boiler?
I know I have to install two drain valves on each side of boiler

Question 4: can I connect the circulator direct to the shutoff switch power? And also, does anyone know got the heck to undue a 3” Flange stuck on a piece of black pipe!? Lol