If it is originally in your hand, then yes, you may send the Machina Fortress in hand as well as one other monster, and then special summon that same Machina Fortress from the graveyard.
Yes, Machina Fortress can be discarded as part of the cost for its own effect, and then that same Machina Fortress can be special summoned from the graveyard.
Machine Soldier can special summon Machina Fortress, as it is a Machina monster. Machina Fortress has an inbuilt special summon method, but this is a 'you can' and not a 'can only' thing, it can be special summoned by other effects if you wish. Since Machina Soldier is a machine, you are also allowed to use it to pay towards Machina Fortress's own special summon cost.
Neither, Machine Fortress' special summon effect is not one that activates.
The turn player sends the material monsters to the graveyard, and places Chimeratech Fortress Dragon on the field. The summon is not yet successful, here is where you'd negate it with cards like Solemn Judgement or Steelswarm Roach's quick effect. So you'd pay Steelswarm Roach's cost and start a chain. Steelswarm Roach's effect will resolve, negating the summon. Chimeratech Fortress Dragon will go to the graveyard.
No, unless stated otherwise, a monster special summon effect works from the hand. Treeborn Frog special summons itself from the graveyard, because it says so. DD Survivor special summons itself from the removed from play zone, etc. But Dark Armed Dragon can only special summon itself from hand.
No, Aqua Spirit can only be special summoned from hand that way. The only time a monster can summon itself from a different zone, is if it specifically says it can. Plaguespreader Zombie is one - it states that it summons itself from the graveyard. But without such text, then they can only summon themselves from hand.
No, unless specifically stated otherwise on the card, a monster's special summon requires it to be summoned from your hand, or in the case of Synchro and XYZ monsters, from the Extra Deck.Plaguespreader Zombie can special summon itself from the graveyard because it says it can. But you cannot use for example, the special summon requirements on Chaos Sorcerer, or an XYZ monster, while they are in the graveyard.
A person can use Monster Reborn then Inferno Reckless Summon to summon Machina Cannon in Yu-Gi-Oh. A person may also use Machine Duplication to complete this action.
No. The special summon text of cards like Scrap Orthros only apply while the card is in hand, unless stated otherwise.
A monster's special summon method, unless specifically stated otherwise, is from hand only. You can remove a Light and Dark monster to summon Chaos Sorcerer only while it is in hand.Plaguespreader Zombie is an example of a monster who can special summon itself from another zone, the graveyard in his case.
No, the only time a monster can special summon itself from the graveyard, is if it specifically says so - Plaguespreader Zombie for example. If it doesn't specify, then the default zone for special summoning is from the hand.
No. Machina Cannon states "Must be first special summoned (from your hand) by..", and this is the only way it can reach the field initially. If you do this, and then the Machina Cannon is destroyed, then yes, it can be summoned by Monster Reborn. But the other two copies of Machina Cannon in your deck cannot be summoned by external effects, Inferno Reckless Summon would not work.