In CR11, everytime you apply a template, it pretty much wipes out everything else on the report and replaces it with what is in the template, so I not sure how you could apply multiples.
It seems that formula don't carry over (I don't use the parameters, but suspect not) as they are data specific, and BO probably assumed (and I would probably agree) that the likelyhood of 2 reports having the same parameters and data schema is unlikely, and so the parameters and formulas would not work regardless, and to not update them.
HTH