What exactly are we voting on? Both pictures are the same bath, only from different angles. In any event, I think you will get more responses and useful advice if you post a dimensioned floor plan of the room, including the adjacent spaces.

$25k sounds low to me given the increased cost in labor and that Austin is an exploding market.

I would definitely run your new tile floor into the closet. For that budget, you will need to keep plumbing where it is currently, choose finishes wisely, and likely keep the vanity. You can change out the vanity top with a prefab slab and add undermount sinks. If you don't use the tub, and you still have another one somewhere in the house, I would remove it to expand the shower slightly. You will be left with a space in that corner and need something there so it looks intentional.It's possible a smaller stand alone tub would fit on the diagonal. Get a couple contractors or bathroom designers in to give you bids and check by calling references or better yet get a referral from a neighbor or someone you know that has had work like this done. There are lots of shady contractors out there.