This almost seems like baseball, collectively, trying to depress his value, not for economic reasons, but to convince him not to play as often as he'd like. Which may be fair enough, but I suspect the team that get him will be the one that is most open-minded and willing to gamble. Highest risk, highest reward.
Because yeah, not using him often enough as a hitter would become a self-fulfilling prophecy. A big reason why pitchers are bad at hitting is because they simply don't get to hit enough (in games or BP). And if he's just an adequate bench player offensively, that's still a nice bonus. The reliever idea is intriguing but I think there is zero chance a team could talk him into that. Maybe later.