Not by canon. See Awaken the Slumbering Corpse, ReCo Base 10 (p 134). "Simple Orders", no Mentem (and all the "intelligence" of any dead body.)
Who says you need to? You are not creating 100 Individuals, you are creating the "Group", which, as a concept, is what you are touching. The 10 (or 100) are all created at your fingertip - they are there, right next to you - but not every Individual is there.
See canon spell Curse of the Ravenous Swarm, CrAn 45 (p 117)
(edit - what ET said.)
My bad. Thanks for correcting me.
Have a look at Thge Walking Corpse though thgis has the Mentem Requisite. I think if you're concentrating on the spell like Awaken the Slumbering corpse, then I could see you having a remote control like effect, but if you're going to leave them then I'd add the requisite because otherwise they would indeed have the intellegence of the dead....i.e. none.
EL
And as I said before, there's The Walking Corpse who looks very much like what he intends to do.
Well... ain't that just great. (Guess that's what happens with multiple contibuting authors)
As SG, I would rule that the difference is "simple" commands" (Walking Corpse) vs "very simple" commands (Slumbering Corpse). The fact that the former goes on to say "unimaginatively" implies there can be some room for interpretation, which in turn implies more complex than "very simple".
Yeah, it's thin, but it's there. 
It could be worse - it could require you to concentrate on their every action. We're neither talking about Verditius Automata nor about Mechanica of Heron, which can act autonomously.
the rule I would say is that unless you have the requisite you will have to direct the undead almost blow for blow in combat.
A
Same thing here.
I want to go back to the group size question for a minute. I think a group of skeletons could comprise 100 individuals. A dry skeleton weighs somewhat less than 10% of a person (the corpus individual), so a group 10 corpus individuals can be 100 skeletons, just like a group of animal individuals can be thousands of insects. Mass is the key.
Arguably.
But "volume" could be another key, and the rough volume of a skeleton (not the absolute volume, but including the area encompassed by the ribcage & etc) is approximately the same. That is, a skeleton is ~roughly~ the same size and dimensions as a corpse. (And with an eye to spell balance, summoning a skeleton warrior is not 1 magnitude less useful than summoning a zombie warrior, imo.)
And even within a Form, the mass of one manifestation of the Form is not always equivalent to a different manifestation.
Lastly (and perhaps most importantly), the Guidelines draw no distinction between a corpse and a skeleton, only in one instance between a full body and a part of the body (see ReCo Lvl 2).
So your interpretation is using the Central Rule (p 111), and not drawn from canon.
(And I'm assuming ~you~ know that last part - I tend to include a full commentary for newer players.) 