You can never tribute something you don't control unless the effect specifically lets you.
So Soul Exchange, Trap Eater, Lava Golem are all examples of something that allow you to tribute your opponent's cards, and they all clearly say so.
But if there is no text allowing it, then by default, it can only be a card you control, ie, something on your side of the field.
Yes, you can attack with the Tribute Summoned monster unless a card effect tells it not to or it is after the Battle Phase.
Yes, of course you can. You can tribute it for the cost of an effect, or in main phase 2, for a Tribute Summon.
You can definitely tribute a monster on the same turn as a Normal Summon, ie, you can normal summon Exiled Force and tribute it for its effect. What you can't do is tribute it for a Tribute Summon because this is another Normal Summon, you can't perform two in a turn unless an effect allows you to do so. But you can tribute that monster for other things, like an activation cost or for a special summon.
Summoner of Illusions states "Tribute 1 other monster". It cannot tribute itself for its own effect.
As Destiny Hero - Plasma's equip effect is a "Once Per Turn" effect, yes it can, and the existing monster is destroyed.
Tribute a WIND, EARTH, FIRE and WATER monster. destroy all cards your opponents controls
You can tribute a monster when an effect instructs you to, or you need to do so as a cost. So you can tribute a monster for a tribute summon only in your own main phases, when there is no chain in progress. You can however tribute a monster for one of Enemy Controller's effects at Spell Speed 2, in either player's turn, in any phase.
No, you must tribute another monster using cannon soldiers effect.
Depends what for. You could tribute it for a spell speed 2 or 3 effect such as Enemy Controller, but not for an Ignition Effect.
Yes, nothing stops you from doing it unless the effect removed the monster from the field.
Yes. If the tribute is for a Tribute Summon, then you can't attack with any monster again afterwards, since this Summon will occur in Main Phase 2. If the tribute is for a card effect and resolves during the Battle Phase, then you can attack again with another monster, since it would still be the Battle Phase.
Yes, you can attack with the Tribute Summoned monster unless a card effect tells it not to or it is after the Battle Phase.
It does target, it targets the monster you want to tribute. After Soul Exchange resolves, that one monster now has a lingering effect applied, that lets you use it as a tribute instead of tributing one of your own monsters.
Yes, of course you can. You can tribute it for the cost of an effect, or in main phase 2, for a Tribute Summon.
If you mean for its own effect, then no. It is an Ignition Effect so can only be activated in your own main phases.
You can definitely tribute a monster on the same turn as a Normal Summon, ie, you can normal summon Exiled Force and tribute it for its effect. What you can't do is tribute it for a Tribute Summon because this is another Normal Summon, you can't perform two in a turn unless an effect allows you to do so. But you can tribute that monster for other things, like an activation cost or for a special summon.
Summoner of Illusions states "Tribute 1 other monster". It cannot tribute itself for its own effect.