Length of time to tumble rocks

there was an interesting thread on tumbling rocks several years ago
that gave me some ideas for my 9 yo daughter's rock tumbler, but
didn't answer my basic question. We've been tumbling the rocks for a
week as per the directions in the Thumbler's Tumbler, Model T, with
the coarse grit. The rocks were purchased from Eggers Lapidary in
Golden, and were a mix of various same hardness rocks, some sliced,
some part way toward becoming cabs. We planned to switch to fine grit
from coarse tonight, but some of them seem to need more tumbling- they
have matrix on them and some of the cut pieces haven't smoothed enough
on the random edges to be interesting. My daughter resisted adding
more time, but I talked her into one more day on the coarse. Will it
make much difference for rose quartz hardness rocks? Will fine grit
do much more or just smoothing? I hate to do what my father did when
I was a kid- grind and grind until there were holes in the tumbler and
the rocks were half gone- but I also don't really want to quit now if
a few days will give a much nicer finish.

do you think it's my imagination or does the process become quieter
over the course of a week as the major rough edges get knocked off?
When they're done, will my Dremel make holes for beading or do I have
to rely on cheap findings to glue on?

=====
Kate, http://www.cs.colorado.edu/~kolina/a...f-formula.html
Mom to Ursula (9!), Sage (6.5), Benno (3!!) Things perfected by
nature
are better than those finished by art. ~Cicero