Since iClone 6 and 3DX6 has been removed from Reallusion hub and the only other programs I use are Crazytalk 8 and Character Creator 2, do I need Reallusion hub at all?

As long as you have the full installers for those two (in case you need to reinstall), there is no need for the Hub. 

Actually, all of these can still downloaded from your account, so it may be good to save those as a backup.

---

yes all in my account still, the disappearance from hub just concerned me as I use them often even though older versions 

That may be an error, because 3DXchange 7 also suddenly disappeared. Did your stuff disappear recently?

On the RL account page it says under product registration that the last three versions are being provided for download so that should also be the case for the Hub I would think.

---

yes, even iClone4 still in my downloads not iC3, NA
iC5 never was as a beta tester gift
and yes vanished previous hub update