Gladiator Beast's Battle Archfiend Shield, Heart of Clear Water, Silver Wing, etc.
Yes, Equip Spell Cards target when they are activated.
Equip cards can never be attached to Set monsters. They can only ever attach to a face-up monster.
You have to summon them first - they equip by using their Ignition Effects, which can only be done when they are on the field in the monster zone.
They are considered to be 'Equip Cards' but not 'Equip Spell Cards', in case anything specifies the latter.
XYZ material monsters no longer count as being monsters on the field, any equip cards will fall off, they will go to the graveyard. Ekibyo Drakmord can only return to hand when it destroys the monster it equips. In this case it will simply go to the graveyard and can't return, it went there as its equip target became an invalid one.
If you mean Union monsters then yes they do, as will any monsters turned into Equip cards by monsters such as Destiny Hero Plasma or Koa'Ki Meiru War Arms.
Yes, Equip Spell Cards target when they are activated.
Equip cards can never be attached to Set monsters. They can only ever attach to a face-up monster.
Yes, monsters acting as Equip cards are treated as Equip Spell Cards and are treated as such for the purposes of Spell destruction card.
Yes. Monsters that are acting as Equip cards, are considered to be Equip Spell Cards and are affected by everything that normally affects Spell Cards. So spell destruction cards will affect them while monster destruction will not.
Face-down monsters are indeed monsters for the purposes of cards which count monsters on the field or affect all monsters.However, if a card effect specifies a monster with a specific type, attribute, ATK, etc., it will ignore face-down monsters because those values are unknown in game terms.Note: monsters used as Equip cards are not considered monsters.
You cannot voluntarily move an Equip card from one monster to another, or unequip it and have it be destroyed, unless another effect lets you do so. Tailor of the Fickle is one card. The other situation is with Union monsters who turn into Equip cards. These can unequip themselves as an activated effect and summon themselves back to the monster zone.
You have to summon them first - they equip by using their Ignition Effects, which can only be done when they are on the field in the monster zone.
Monsters that can equip to monsters.
They are considered to be 'Equip Cards' but not 'Equip Spell Cards', in case anything specifies the latter.
If a monster ever finds itself in the S/T zone, it ceases to become a monster, and is now a Continuous Spell Card. It loses all effects, cannot attack, nor is it affected by cards that specifically affect monsters. The only exception to this are monsters that become equip cards (like Unions and Dark Necrofear), and only when they use their own effect, never when they are forcibly taken by cards like Relinquished.
No, face-down monsters cannot be equipped.