#7 only applies,
if you plan on ruining your music,
by applying way too much limiting and compression at the mastering stage, as is most commercial releases today.
leaving a mix with plenty of headroom,
if you know you are going to be applying limiting to bring up the overall volume,
is smart,
as long as you don't chop off all of your peaks.
and if you do,
your stuff will sound as hammered and harsh as most modern commercial masters.
there ARE some mastering engineers,
who have figured out how to eq the top end,
so that HEAVY limiting does not sound so harsh,
but this all depends on the end user....
are they listening on ear buds for hours at a time?
are the streaming thru their phones?
are they sitting and listening on a high end audiophile home stereo or theatre?
do they have regular bookshelf speakers in an office?
the whole idea of mixing,
is to get your best sounding mix.
it should sound wonderful without any mastering.
the whole idea of MASTERING, in my opinion,
is to get whatever else you can out of the headroom,
without ruining the mix, or changing the overall sonics.
there are many commercial releases i have bought over the last year,
that i do not listen to anymore,
because it sounds harsh to me.
YMMV