Yes it can, because as it leaves the field, the effect resets.
Not unless the monster specifically has a restriction on its card.
Ra's attack and defence is equal to the combined attack and defence of the monsters tributed for its summon. You can also tribute other monsters to increase Ra's attack and defence by that monster. When Ra is summoned from the graveyard (monster reborn etc.) it has 0 attack and defence as no monsters were tributed for it
Yes, this is legal. You have two main phases, one either side of the battle phase, there is no rule that says a monster that attacks can't be tributed, or that attacking stops you summoning. You can attack with a monster, then tribute it for a tribute summon in main phase 2.
yes
As long as you are Special Summoning before, or during the Battle Phase, then yes, that monster can attack.
Unless another card specifically denies the attack or if it was Special Summoned AFTER the Battle Phase, then yes the Special Summoned monster may attack.
Assuming the defending monster is also in attack position, both monsters will be destroyed.
Yes of course. Special summoning never affects what can attack or not, unless specifically stated otherwise. You could normal summon and special summon a monster in main phase 1 and attack with both.
If you have a level five or higher monster in your hand, you can tribute one or more monster(s) on your side of the field to play it. If a card's cost/flaw (ex.mystic wolk:tribute one monster. Gain life points equal to the original attack of the tributed monster) activates, that tributes as well.
depends if the monster has any special conditions under "effects" if its a normal monster then yes you can attack after summoned if its an effect monster and it doesn't say anything where you have to wait then you can attack the same turn. Hope this helps
Your monster is destroyed if the monster you attack is in attack position, and you lose life points.
the monster still gets the bonus of attack points hope this helps!