not all. you can hit alot of single legs with no grab. and an underhook can be substituted for a cog grab. i like an ungrabbed underhook to start with and then use the grab to finish the throw because the grab disrupts the ghost so you are a turn ahead of them. evidence that this works
Mid section- That's not a real life technique. I guess you could say it bears some resemblance to osoto guruma.
Perfection- It's osoto gari.
Push counter- That looks like a hip throw.