Do black holes contain "dark matter"
NO.
Given >90% of what we cannot observe is claimed to be this stuff then black holes must have a mission on chorus of such stuff.
because the math is incorrect with the observed data
see a basic wiki
http://en.wikipedia.org/wiki/Galaxy_rotation_problem
How would black holes behave with such extra stuff - well I can only ask.
you can paint the same pretty picture as anyone else
the computers used are only as good as the math put into it
but be certain, no dark matter/energy exists
it's all proof of the failures of much of the sciences and the worst part about it is, there are many still trying to sell it for funding
i.e.... see the billions lost in accelerators and that math alone ruins any dark matter junk through and through
the missing link is the energy between mass is entangled