No his kit is fine... His base state is not. One of the worst HP and Armor of all champion. All he need is lower the cooldown on his E and/or maybe change the energy cost for that skill.
He has one of the worst shitty armor and HP of all champion, even sona is tankier than shen xD But at the same time, Shen can super tanky with all the shield and W :/ When he is ahead, he can be unkillable only with a few items dispite the shitty armor and HP and deal lot of single target damage.
When we think about that, I think shen is fine where he is or else riot will just nerf him later. So keep in mind, he can be very tanky with items and bad stats, prove that his kit is strong but you need to understand his mechanic in the first place.
Maybe I say that becaue he is my main and I dont want him to be FOTM or perma ban -_-
Rip me.
Anyway, Shen is strong, not OP, but if riot buff him, he will be OP, sad reality.