can hover move type enter hindering? If they can, can they move freely into and out of it?

No. Hindering terrain is blocking for movement purposes to hover units. No part of their base may enter it.

Tracked units are the ones that may move through hindering as if it were clear. All units are still affected by the +1 to defense when their line of fire crosses any hindering terrain, and camo bonuses if the target's centerdot is in hindering. Except for JF, who's Enhanced Imaging faction ability can negate that.

Not completely correct.

During movement a hover units base can enter hindering as long as the center dot does not. At the end of movement no part of a hover units base may overlap hindering.

Except cruising VTOLs.