Firstly I would advise against running more than 2-3 profiles.
Secondly make sure your machine specs are capable of running all those profiles.
i5 processor or higher .. allow 2Gb Ram per profile, plus 2gb for the OS. (This is generous, but safe)
if you are capable of the above ... set request limit to no lower than 6 and no higher than 22 if you add up all the profile instances. At 5 the previous version of MFP used to struggle to perform certain tasks ... haven't checked v7.