Yes, monsters acting as Equip cards are treated as Equip Spell Cards and are treated as such for the purposes of Spell destruction card.
If you or your opponent activates Heavy Storm and you chain by activating Mystical Space Typhoon and target the activated Heavy Storm, the chain resolves backwards. The effect of Mystical Space Typhoon destroys Heavy Stormas it is placed on the field when activated. However, the destruction of Heavy Storm does not negate its effect and, as it is Chain Link 1, its effect resolves last destroying all Spell and Trap cards on the field including the activated Mystical Space Typhoon.
Yes. Mystical Space Typhoon destroys its target. Destroy is a specific kind of send, so will satisfy Hysteric Sign's activation condition.
Yes, they can. You can also play another field spell to remove the one that is currently in effect.
Mystical Space Typhoon will still resolve fully, but Scapegoat will have resolved first, before it did so. Mystical Space Typhoon is not a negation card, all it does is destroy a target, and in this situation, it did just that. It would not be accurate to say Mystical Space Typhoon has 'no effect' here because it did still resolve fully. If any card looked for spell card resolutions, or card destruction, the above scenario would trigger them. However apart from that, the Mystical Space Typhoon is doing nothing more than destroying a card that was about to go to the graveyard already.
It cannot negate the activation of a trap card. It is basically the opposite of Magic Jammer. Mystical Space Typhoon can destroy face down spells and traps, continuous spells and traps, and field and equip spell cards.
Cards resolve in the opposite order that they are activated in. So, your Mystical Space Typhoon will be chain link 1, and their Trap will be chain link 2. That means their trap will resolve first, and MST will resolve afterwards.
You don't, these things destroy you!
You can never destroy, discard, or otherwise send to the graveyard a card unless directed to by a card effect or a game rule. The exception is a Field Spell card, you can replace one with another even though the first is occupying your Field Spell card zone.
Mystical Space Typhoon Heavy Storm Dust Tornado You can simply activate a new Field Spell to destroy any currently active one.
This is because usually typhoon is accompanied by:strong wind,tornadoes, andheavy rain.
A typhoon can destroy infrastructure and peoples because of high winds and rain. The rain leads to flooding and the high winds can sometimes lead to high ocean waves that destroy fishing vessels.
No, you cannot. Source: I'm a 6 year Tournament Player. That's assuming the original question was asking if you could voluntarily destroy your own trap cards for no reason, without it being part of an effect. You can freely target and destroy your own traps with cards like Mystical Space Typhoon though.