Heatform / Heatilator - Information regarding upgrade to Wood burning Insert

[GarlicLover]

Hello,
My wife and I just bought a new house recently that was built in 1965 and it has a Heatform style fireplace. We don't have any information from the previous owners but it was changed to a gas fireplace at some point as you can see on the pictures. I read that usually you can install an insert in these without any issues but I have a few things I would like to ask.

1. They cut a whole on the right side for the air intake and gas line. Could that be patched before installing the insert ?
2. I read that you can install a 6" stainless steel flue inside the current 8" flue, but It seems that right after the damper where the flue begins there is a 90 elbow would that still be feasible ?
3. What would I do with the "Air Chambers" on the side if I install an insert ?
3. Overall you think installing a wood burning insert is something that I could do with my current fireplace ?

Thank you very much ! : )