The cable pull is the same as "non-aero" levers, so no problems there.
not quite so, aero levers have more leverage, MA,
pull less cable for the hand lever motion, than cable out the top levers..
[though some of those 'safety levers' sit in the lever arc,
so it doesn't swing as far open]
NB: You can just remove the extra lever, keep the main brake lever,
and re adjust the existing brakes.
[did this on a repair . step 2 would be saw off the end
of the pin the lever rotated around so it was flush
the inside of the .. metal 'Hood'