Full Edwardian refurb, how to begin?

[pondlife900]

Hello all, I hope you are keeping well. What a great resource this is. We are buying a 20s house that hasn't been altered in a long time. It needs full redecoration, rewiring and a new heating system. The surveyor today said the house is great and doesn't have any red flags. His main recommendation was knocking out the chimney breasts as he said the roof chimneys had been made smaller over the years and are deteriorating a lot, and unless used, it's not worth having to keep repoint them every few yrs. (Note that I would love to salvage and restore at least one open fireplace in future). I wanted to do some light structural work to bring a gap in between the kitchen and the room alongside. But now I am now tempted to remove this thick slab in the kitchen & the broad lintel above it (which I now understand is a problematic chimney stack that has been modified many times and is potentially bringing moisture into the loft space), but I know this will mean work right up to the roof, asbestos check in the loft etc (& probably roofer will want to re-roof the lot as tiles are original). Our budget is about 120k & we are not doing any of the work ourselves. The priority is also to live there as quickly as possible as we are renting. I attach an image of the "stack" and what I believe my ideal vision is for the eventual layout. Note the kitchen is a solid slab floor and the adjoining lounge is timber floorboards. I am not sure what that stack affects on the upper level, but I would ideally like to make the bathroom smaller anyway and create an open plan snug on the landing. There is a big loft that has great scope for another room with bigger bathroom but this be a future consideration. As it will be a while before I can view the house again and bring some experts in (have been asked to wait until elderly vendor goes to his new home within a few weeks), I wondered if you would care to give your opinion as to whether removing this stack is worth doing right away & likely cost implications. Also, whether it would be possible to do a phase 1 that makes the house liveable in budget but still achieve the slab-less vision in future without too much collateral damage. Thank you!

[pondlife900]

Posted in wrong place - would a moderator please delete this post, I've reposted in Structural advice. Thanks.