No it can't, only from your hand if you have exactly 3 DARK monster in the grave.
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. If a monster says it 'cannot be special summoned except by', then the listed method is the only way it can reach the field. By default, this summon is from the hand too. So, even if you properly special summon Dark Armed Dragon, and it goes to the graveyard, you cannot special summon it using either its own special summon effect, or the effect of cards like Monster Reborn.
Unless specifically stated otherwise, a monster special summon method is for when it is in the hand only. So Treeborn Frog special summons itself from the graveyard because the effect says so. But Cyber Dragon special summons from hand - even though it does not say so, the hand is the default zone, it cannot special summon itself from the gfraveyard. Likewise, Hardened Armed Dragon must be in your hand to use its special summon effect.
Armed Dragon LV 10 can only be summoned with the effect of Armed Dragon LV 7. Once you get that out and keep it out long enough for its effect to activate, tribute the LV 7 to call out LV10.
To obtain Armed Dragon LV7 in the Yu-Gi-Oh! Trading Card Game, you typically need to first summon Armed Dragon LV5 and then use its effect to send it to the graveyard, allowing you to special summon Armed Dragon LV7 from your hand. Additionally, you can search for it using cards that specifically retrieve or support the Armed Dragon archetype. Be sure to check your deck for any specific support cards that can help in summoning or searching for it.
I'm assuming this is a TV show question. And the answer is Yes.
DAD refers to the Dark Armed Dragon, a monster that can only be special summoned when you have exactly three DARK attribute monsters in your graveyard. Dark Armed Dragon's effect allows it to remove a DARK attribute monster in your graveyard from play to destroy a card on the field. Combined with Dark Armed Dragon's 2800 attack points, this makes for a quite powerful monster.
Special Summon Quickdraw Synchron by discarding Plaguespreader Zombie.Normal Summon Stardust Xiaolong.Synchro Summon Turbo Warrior.Activate the effect of Plaguespreader Zombie from the Graveyard by sending Majestic Dragon to the top of your Deck.Synchro Summon Stardust Dragon.Activate the effect of Stardust Xiaolong.Activate the face-down One for One by discarding Mad Archfiend to Special Summon Majestic Dragon from your Deck.Synchro Summon Majestic Star Dragon in ATTACK POSITION.Activate the effect of Majestic Star Dragon and choose "Negate monster" and designate Dark Armed Dragon.Activate the effect of Majestic Star Dragon and choose "Activates the effect of the negated monster" and Remove from Play Mad Archfiend as the cost. Then select Dark Armed Dragon as the target of the effect.Enter BATTLE PHASEAttack Directly with Majestic Star Dragon.
No you can only summon lv 7
Yes. Hardened Armed Dragon doesn't need to be face-up. The effect is not on that activates, it's just something that's checked after the tribute is paid.
It is an Ignition Effect, so can only be activated in your turns.
Special Summon Quickdraw Synchron by discarding Plaguespreader Zombie.Normal Summon Stardust Xiaolong.Synchro Summon Turbo Warrior.Activate the effect of Plaguespreader Zombie from the Graveyard by sending Majestic Dragon to the top of your Deck.Synchro Summon Stardust Dragon.Activate the effect of Stardust Xiaolong.Activate the face-down One for One by discarding Mad Archfiend to Special Summon Majestic Dragon from your Deck.Synchro Summon Majestic Star Dragon in ATTACK POSITION.Activate the effect of Majestic Star Dragon and choose "Negate monster" and designate Dark Armed Dragon.Activate the effect of Majestic Star Dragon and choose "Activates the effect of the negated monster" and Remove from Play Mad Archfiend as the cost. Then select Dark Armed Dragon as the target of the effect.Enter BATTLE PHASEAttack Directly with Majestic Star Dragon.