I would not want a bedroom closet door right next to a shower, let alone 2 closet doors. Can you move that to the nedroom and enter from their? For a curbless shower you will need to sloope the floor joists system. How is the floor constructed and can you get to the joists to work? What is the the floor joist system and have you had anyone check if altering them is possible?

I have never been a fan of closet access from the bathroom myself, but adding a door from the bedroom isn’t possible. The house has wooden joists running perpendicular to the wall with window over the tub. i guess there would be cement under the shower area; there is no basement or crawlspace underneath, so it‘s not really accessible. i’m guessing that would make the curbless shower cost prohibitive, so we may have to settle for a low curb.

If you want to keep a tub, remember that in time it will be more of a hindrance, not just to use but by its very presence. If you are planning for mobility needs requiring a curbless or low-curb shower, you are probably planning for a mobility assistance device, such as a walker or rollator, or more. It is hard to maneuver around a tub. You might consider a tub with less deck behind it. I hope you plan to change the door swing to the other side, too.

I definitely want a soakining tub, but not freestanding and not bulky. Something more like this drop in one. Good point about the door swing! Forgot about that door on drawing.

For the long double-vanity idea, I would draw the wall elevation as well as the floor plan before deciding how much cabinetry to buy. Mark both sink centers, the mirror area, lights and the everyday storage each of you needs. A long countertop does not necessarily need a full run of overhead cabinets or one enormous custom mirror. Comparing standard cabinet widths and separate mirrors with the custom options would give you a useful cost comparison.

Since you are planning ahead, mock up the mirror and shelf heights for both standing and seated use, and try the drawer pulls and light controls in person. Keep the items used at the sink in that zone so the linen closet does not become the daily toiletry cabinet. These details can go into the same brief you give the bathroom designer. For budgeting, ask for one layout that retains the existing plumbing locations and a second with the long vanity, with the relocation work priced separately. That should make it easier to decide which changes are worth paying for.