Not sure if Oda will pit Yamato against an opponent in the same league as Zoro and Sanji... Even if she's in the same league as the Wings, Oda will trick the (naive) readers that she isn't by pitting her against a lesser (but advantageous) opponent...
Zoro is too much of a Gary Stu now, and it makes him less interesting for me. His getting lost is more of a gag than an actual flaw, and I prefer his pre-time skip characterization much more. Why anyone likes this in a Strawhat is beyond me.
How is that even a question?
Law is a human. An incredibly tough human but bullets, swords and nails (especially nails) will always be able to hurt him, let alone a named attack if he doesn't defend himself.
The RS is an armor that normal bullets can't even dent and, whatever someone thinks about Sanji>=< Law, Sanji is not physically weaker than Law.