I just had a contractor quote residing our house last Thursday. (Going over T1-11 plywood siding with hardiplank cement siding)
1. Behind electrical meters, water faucets, lights, or anything else attached to the exterior wall he uses flat rectangles of hardipanel fiber cement board. That goes over the new house wrap, flashed at the top, and is painted to match.
https://www.homedepot.com/p/James-Ha...0525/202035433
2. I would demo that chimney. I'm thinking of doing the same for my working chimney / fireplace. We never use it and it takes up a bunch of room in the garage. A chimney also increases insurance cost.
3. Here in the Pacific Northwest the deck material of choice is cedar if you don't want pressure treated or plastic engineered decking.
EDIT: Personally I prefer patios to decks. I would pour a slab to replace the deck. If you want to get fancy you can tile it.
