I just bought a house. Front half is pier and beam (2x10 joists @ 16" centers, max span of 13') while the back half is slab (hairline fractures at most, no height difference at fracture points). The back half was an addon about 18yrs ago, while the front half was built ~50yrs ago. Sawmill lumber was used for all structural support and framing on front half, standard 2x construction on back half.
Floors in the front half are (sawmill) 1x12, 3/4 plywood over that, and 3/4 oak hardwood floors on top of that. The hardwood had been sanded/planed down over the years to ~1/2" thickness. There is the dining room, living room, kitchen, bath, and bedroom in the front half.
I'll be having 12" tile in the kitchen and bath. The dining and living room will be wood (either composite or the plywood laminate type) with tile border (12") around the perimiter. The bedroom will be wood with a tile mosaic in the entry.
There is no code enforcement in the town where I bought my home and rather than trust the local flooring "guy" who is liscenced, but would not supply references (my asking offended him...), I'd appreciate some feedback on his suggestions. Primarily on the front half of my home.
I'm looking for feedback on what should be done for the floor prep prior to floor instalation. I can add up to 1 1/4" to my floor thickness if needed at most (the front and kitchen door thresholds are 1 1/2" above the current finished floor...they seem to have been original. Not sure why.

Everyone who stops by trips over them)
He suggested 1/2" plywood in the dining/living/bedroom areas and 1/2" hardibacker in the kitchen and bath.
I just want this done right the first time.
My main concerns:
Would the tile border in the living/dining and the the mosaic in the bedroom be ok if set on the plywood?
Would durarock be better in the bathroom and/or kitchen than the hardiboard?
Would glue be enough to hold down the wood floor in the living/dining? I'd really like to have the tile border, but I also want this floor to last.
I appreciate any feedback or any helpful suggestions on what else to look out for.
Edit: There is also a fireplace in the living room, and i'd have a 2'6" x 4'6" tiled area in front of it which he was also going to just put directly on the plywood. It will recieve quite a bit of traffic. Is that acceptable?