We have a smallish master bath that I've disliked since moving to this house. The shower is cramped, the floor tile is slippery, it's dark, etc. We've been saving for a while and the discovery of gunk growing out of the baseboard on our bedroom side has convinced DH that it's time to reno. Everything is circa 1984 and the house is on a slab foundation in Texas, near Galveston. We'd have to dig out the concrete to move drains.

Our DIY experience is mostly cosmetic. We can put in light fixtures and sinks/faucets, but totally think a plumber earns his money! Slime/smells make me gag. We'd certainly be able to demo it ourselves, though.

Below is the bath as it currently stands. I drew the door swing for the shower incorrectly, it actually swings out and interferes with the door swing into the room.
I'd like to keep costs down, so moving the plumbing is a last resort. However, to get a well-funtioning room we'll suck it up to get it right.

The plumbing for the shower is in the wall next to the toilet. I'd like to move it to the short wall and install a glass partition between shower and toilet to increase elbow room. Then lengthen the shower toward the vanity to 4 ft and leave it open at the end-no door. Not sure if this will be allowed even with a curb for the glass wall. Maybe a tub would work?
We'll have to dig and move the drain to the right wall, since it's currently in the bottom left corner.
I'm tossing around the possibility of installing a radiant mat and/or Panasonic Whisper/Warm to compensate for no door. Being on a slab, those floor tiles are uncomfortable during cold weather!

The vanity has a 1 1/2" drain, so I believe that we'll be able to tie in the plumbing for two sinks according to IRC, as long as we pay attention to sink placement. Personally, we don't need a double vanity and I'm still undecided between 1 or 2 sinks. However, if we choose to sell, this will be a benefit. We don't plan to move any time soon, but you never know.
I'd like a lot of storage, so keeping the vanity where it is will allow that.

I want to use a barn door, placed on the bedroom side, as access into the room so door swing doesn't interfere.

We have a bedroom, on the other side of the toilet wall, that we could use for a bit more space, if necessary. I want to keep it, though, as it's used as an office/guest room and will eventually be used by one of my boys when they no longer want to share. The wall behind the vanity is our closet, 5 Wx6.5 L. I can see taking space from there if we get a closet system to maximize what's left. Budget is an issue, though.

I've been drawing for a while, and would love fresh eyes! We are firmly in middle class territory, here, and our house is one of the larger in our neighborhood at just under 2000 sq ft. People don't expect grand, but I'm sure they'd like to be able to wash their hair without bumping the shower walls.

Thank you for any advice. I'm driving myself crazy with "what ifs".