We are building as well, our ensuite is similar size. We are having double tiled shower, double vanity and toilet. We didn't separate toilet as it was a added cost and didn't see the point in the master

Based on the dimensions you have given and the religious aspects you mention you are very restricted in what the layout can be. The best solution I see means you have to move the door towards the south by 36". I suggest you make it a pocket door retracting towards the south wall. This leaves 36" x 60" of space on the north wall for either a shower or tub. The vanity would be on the west wall ( across from the door) spaced away from the tub or shower around 12". Make sure the vanity cabinet is shallow, no more than 21" deep. The vanity should be able to be about 48" wide. The toilet will go on the South wall with the right side of it close to the East wall. Code calls for approx. 33" of width for the toilet overall. If budget allows you could continue the vanity cabinets into the corner of the south wall however keep in mind that most of that area that will be next to the toilet and not easily accessible. But it would provide extra storage or counter space. The sink will have to be centered in the 48" part of the vanity. You could also frame out the southwest corner to capture the side of the vanity instead of a longer vanity. Hope this helps.

Leave the vanity in the ,space needed in a walkin is personal but in a 8 x 8 if you put storage on 3 sides you will have quite a lot of space, figure out what you have now and see if it will all fit or will you need dressers in the MBR

This layout is not what i would ever suggest to a client for starters the MBR and DR are all wrong , who wants to walkthat far with food from the kitchen the DR is completely closed off of the rest of the space just too many things to correct for me.I really dislike homes built to look great from the outside with no proper function on the inside