I'm struggling to work out the precise function of the し in ものを大事にし here.
Well - I'm quite sure it is the し particle for linking clauses, but the lack of a dictionary form before it is putting me off.
Surely it should be ものを大事にするし?
I get お大事に is an expression - that means it would just get the し at the end with nothing in between? (I would have thought [NOUN]を大事に would be different seeing as though it is different..