I have not encountered 5" studs so can't help with that but a good plumber is what you need they will tell ypu if wall hung can be installed From what I can see the waste pipe will be an issue .

I "fess" that I've never installed a wall mount but I don't see a problem with what you propose. I suggest finding a plumbing supply house that will help you with correct fittings. If the existing vent were plastic a sanitary tee or perhaps wye fitting would solve the whole thing but I'm not sure if those are available in copper. You need to prevent any transition below toilet flange that might snag t-paper so a bit of sanding/filing might be time well spent.

Out of curiosity why do you want the wall mount?

The bathroom is pretty small and I need to save space (hence the need for a a wall hung)

The other factor is my wife who would like to be able to easier clean that area

Nope.

A very precious feedback coming from a Pro. I am sure your reply will encourage your potential customers to avoid you :-)

" The other factor is my wife who would like to be able to easier clean that area"

It would be extremely easy for your wife to clean that area if you were to take on the responsibility for that chore.

Apparently I never do it well enough and I am getting lost in the one thousands things she applies to keep the bathroom to the highest standards of cleaners. Don't tell me you never had this problem

The question was can I install this toilet the answer really is no . As for cleaning my advice start to sit down to pee big improvement in the cleaning of the bathroom. Get a one piece toilet with round bowl they fit nicely in small spaces . I have 3 boys and a hubby the rule in our house was you stand to pee you clean the bathroom worked like a damn and the DILs love me for it. too.

I never asked for cleaning advice. Assumptions and advise not asked for like the above are toilette matter for me (trying to stay on topic here). You can't possibly know who does what in our house and why. So get lost. Be a pro and focus on the technical matter not on the life of your customers (potential or not)

and if you want to leave the impression that you are a pro, explain your "no". that is what I would do if I woud sport the badge "Pro" around here. Show your potential customers your are technically more prepared to deal with their projects than with their personal life.

Geee !

Have you considered furring out the wall?

Yes I did. I even considered positioning the entire thing in a corner.

The resulting work in both case offsets the advantages.

the bathroom is relatively small and I do not have a lot of room in that corner where the current toilet is. furring the wall will either create a bump in the wall in the area where the toilet is OR if I do that for the entire wall on that side it will push the vanity in the already narrow area use to access the bathroom (shower in front of the toilet, in the alcove you see there)

Furr the wall out ? Now there's an idea worth consideration and hear me out before saying it's too much trouble or will waste precious space. As for the amount of material and labor required, you knew a wall hanger was 5x as expensive and labor intensive as 99.9% of residential floor mounts. As for wasting space , the end result could actually ADD space compared to present arrangement.

Looking at your overhead view of bath, you can see that bump-out will not place bowl near as far into room as tank effectively does now. No need to bump-out behind vanity, leave it where it is. If you would like a woodworking challenge, consider this in leu of conventional bump-out. From floor to + - 2' above toilet seat, bump-out is enclosed and finished to match wall. From +- 2' above toilet seat to eye level or all the way to ceiling, bump-out becomes a cabinet utilizing wall cavity for adding 5" depth to shelves. Vent enclosed/concealed in it's own 4"x4" 1/4 hardboard/plywood tray. Remainder inside bump-out finished and painted as suitable for a cabinet interior. Face frame doors, hinges and pulls matching vanity. The idea being to make bump-out look intentional.

I already have a buil in behind the mirror above vanity. There is enough storage in that bath, all of it on that very all. There is a closet next to the door as you enter, on the left side. Then it is the vanity and then it is the built in behind the mirror. There is no point in adding 5" of storage depth above the toilet and make the space feel even more packed . The toilet in the picture is not rendered to scale I think, (the top view picture, but it is a normal toilet 26-27" depth)

Cabinet with shelves optional but I still say front of bowl will be nearer wall than presently. If all else fails get one of them room stretchers from Harbor Freight.