No, it doesn't end the battle phase.
No you cant
'Immediately' is misleading, normally you summon in the main phase so you need to wait until the battle phase, it can attack in the same turn it is summoned. If a monster is summoned in the battle phase then usually it can declare an attack as the next game action.
Yes. If you have Ultimate Offering, you can use the effect during the opponent's battle phase. You can use it to do two Normal Summons, yes, you can perform a tribute summon if you wish.
A tribute summon is a form of Normal Summon. So that means you can only tribute summon OR normal summon ONCE per turn.
No, it doesn't end the battle phase.
No you cant
Yes you can but only if you have not summoned a monster already that turn. You can only summon or set a monster once per turn. You can summon a monster during main phase 1 or main phase 2 Draw phase Standby phase Main phase 1 Battle phase Main phase 2 End phase
Horus Lv6 says, that at the End Phase of the turn in which it destroys a monster by battle, that you can send it to the graveyard to special summon Lv8. This means Horus Lv6 must still be on the field after the battle phase, all the way to the end phase. If it gets destroyed during the battle phase, then it cannot summon Lv8.
'Immediately' is misleading, normally you summon in the main phase so you need to wait until the battle phase, it can attack in the same turn it is summoned. If a monster is summoned in the battle phase then usually it can declare an attack as the next game action.
Yes. If you have Ultimate Offering, you can use the effect during the opponent's battle phase. You can use it to do two Normal Summons, yes, you can perform a tribute summon if you wish.
A tribute summon is a form of Normal Summon. So that means you can only tribute summon OR normal summon ONCE per turn.
YES!! Because you have both a main phase 1 and a main phase 2. If you do not summon a monster in main phase 1, enter your battle phase, complete your battle phase, then enter your main phase 2 and you can summon a monster with 4 stars or less unless it has a special effect or tribute the monster that already attacked. Unfortunately you will not be able to attack with the new monster until the next turn, but hey, thems the breaks.
yes you can
Yes, it does have to be in your hand.
Unless specifically stated otherwise (like on Gorz, or Battle Fader) a special summon can only be performed at the same timing as a Normal Summon, ie, in your own main phases when there is no chain in progress.
Yes, in the yugioh card game you can advance summon (this is also called tribute summon or sacrifice summoning).