GK -
Whatever its merits, the V-22's 10,000 lb max payload is not tailored for mass logistics transport.
Also, I don't think the Marines have given a TOSS about TOSS, maybe because of TOSS's TOS, which will make sustaining 24 hr coverage burdensome aboard the amphib.
Yes, you can tanker-drag more F-35Bs into the FOL, but you still need the support equipment and personnel.
Engines - I don't think Gripen is a politically practical option for the USMC. However, it does seem able to handle an 800 m strip (a lot of today's fighters will STO - the harder part is always SL), and together with being designed for very light organic support, and needing around half as much gas as almost anything else, it's an interesting option for expeditionary airpower.
It underscores the general point that you don't need a lot of runway to make your aircraft design much easier. (Which is also the reason why VTOL airliners have never gone anywhere.)