Kind of does negate your point, but it also doesn't.
Look at the video from 0:00 to 0:19
That rebellion combo 1 is possible, rebellion combo 2 with a million stab is possible.
The million stab won't be as fast when a human being does it but it's multiple stabbing that could be done.
Helm breaker can also be done if you jump from a slightly high area. Anything too high would break bones.
High time can also be possible. It won't launch people in the air but it can be done as an upper cut attack, jumping up with them is impossible though.
Stinger can also be done, but again, not with the power Dante has. Maybe for a human being the stinger will look like DMC2's stinger and follow it up with million stab.
Everything else is impossible. However Dance Macabre can be done as well, except the last move where he spins around on his sword.
And it doesn't really matter what sword is used. As long as it's a slightly long sword like a longsword or even a katana (But I use that for iaido.)