Dragunity

When one of the monsters is equipped to another is that equipped monster counted as a monster still or a trap/spell.. and if the latter can it be targeted by cards like mystical space typhoon? If the former.. will cards like effect vieler work on it and if so what happens (does it get ss back to field etc)..

Also how do you unequip them anyhow to bring them back to field to use them in a synchro summon?

When a monster is equipped to another, it is always treated as a Spell/Trap, so yes, it can be targeted by MST and similar cards. On a side note, they still count towards Dragunity Dux' ATK increase, since he specifies Dragunity "cards" in his effect.

For my knowledge, there are only 2 cards that can Special Summon from the S/T Zone (in a Dragunity deck):
1) Dragunity Phalanx (itself)
2) Dragunity Militum (any Dragunity card in your S/T Zone)

You can simply understand this: Every single cards in the S/T Zone are considered S/T (Spell or Trap depends on the card).