Sounds like it will be fine. There probably is an XL shaft but it is rare to see them in use.
I have a F100 Mariner myself.
I have put many hours up on Suzukis as the Bellavista fleet have a couple. Not sure if they are DF's, they are not the current model. There seems to be a lot of new "older model" Suzukis around.
From what I have experienced they are a fine engine. Good grunt and being EFI they are very responsive. They are good enough on fuel, i would reckon they is not much between them and the Mariner but of course it depends on the man with the hand on the throttle
they will achieve around 1NM per 1ltr of fuel on a Warrior 175.
I know that to get the engine serviced by one of the Suzuki Dealers here in Cork was expensive (300-400). I am sure that there are more competitive people out there. After the first service the interval should be around 100hrs. That's probably once a year for most guys. You'll find that plugs are not replaced as often. Something says to me that Suzuki have a short impeller change interval but I'm not 100% on that one.
From what I gather they are reasonably trouble free. BV have not had any trouble from any of theirs. There was a known issue with flywheel bolts shearing at one time.
I know that "Screaming Reels" on here operates a pair of 80's on his craft. He traded a couple of years back and went for Suzuki again.