We're about to finish our basement bathroom that was framed/roughed by the previous owners. The space is 88" wide x 68" deep and 8' tall, minus a couple inches due to the plumbing mains running below joists on the ceiling and general drywall/backing that needs to go up.

The toilet is currently roughed in the back left corner and there is ductwork on the entry side for about 30" into the room that reduces the ceiling to 7' in that area (marked in pink below).

I have a couple of questions:

1. Do we move the existing toilet stack to be on the shower side to run Vanity / Toilet / Shower from left to right? Is that the norm? It would make the room bigger to not have the vanity in the middle IMO. We have to break the slab to add the shower drain anyway so it's just more labor.

2. How do I fit a shower in a 68" deep space? Unless I'm missing something, the logical thing to do seems to be to put a 48" shower base in the bottom right, bump the back right corner of the wall out (basically in line with the vanity depth) and run the 7' ceiling across the shower so it doesn't have a weird step then proceed as normal? Is it worth leaving the toilet as is if that is the solution to tuck the vanity up against both those walls and potentially have two mirror walls or a medicine cabinet type thing? Samples below…

Thanks in advance for your thoughts on the above and anything else!