We have a fireplace we eventually want to add a gas insert to. For now we want to remove the chimney (it leaks and after trying a number of things it still leaks) and repair the roof.

My question is can we remove the chimney in the attic and 2nd floor (the cement blocks and whatever else is there. We are going to remodel the bathroom, so that wall can be opened no problem.

We like the brick fireplace on the first place, and would like it to remain. We are hoping to add a gas insert someday. So will leaving the cement bricks in the basement & first floor be unstable? Or is it fine? Just seems wierd to have this hole from the downstairs fireplace going up to a floor upstairs.

Also – I assume we will need some duct for the gas insert. Can this go out a wall instead of up? Or should we put a vent in now? About how much space does that use up? I assume more than the size of the pipe itself.

Is this something we’d need a mason for or could our general contractor do a lot of it?
Who would actually put in the vent necessary for a gas fireplace, and will we need to know which gas fireplace we’ll buy?

Sorry for so many questions in one. Answering any of them will be appreciated.
How do I know if the chimney is a support for my house?
Our general contractor is a carpenter as is his father (father / son team). Who would I get another opinion from? A mason? A ‘builder’? About what should I expect to pay for this opinion?