yes. in the official Yu-Gi-Oh! rulebook, it states that you can only normal summon once per turn, but you can special summon as many times as you can per turn.
Yes, you can use the trap card Ultimate Offering which you would have to pay 500 lifepoints for each extra normal summon, or there is a spell card called Double Summon which allows 2 normal summons.
Special summon Quickdraw Synchron discarding Level Eater, special summon Level Eater from the graveyard, then sync them. Level Eater -- 1 star If this card is in the Graveyard, you can activate its effect by selecting 1 face-up Level 5 or higher monster you control. Reduce that monster's Level by 1. Special Summon this card from the Graveyard. This card cannot be Tributed except for a Tribute Summon. Quickdraw Synchron -- 5 star You can send 1 monster from your hand to the Graveyard and Special Summon this card from your hand. You can substitute this card for any 1 "Synchron" Tuner for a Synchro Summon. This card cannot be used as a Synchro Material Monster, except for the Synchro Summon of a monster that lists a "Synchron" monster as a Tuner monster.
The only time you can do this is if you are tributing the monster for a tribute summon, or sending them for some kind of special summon, like for Destiny Hero Plasma or a Synchro Summon. But if you wanted to summon another Lv4 monster, you cannot simply make room by sending a monster from the field to the graveyard, you can only do so by effect or game mechanic, like when it is destroyed by battle.
Since White Stone of Legend is a tuner it can be used with any other monster to synchro summon that is allowed
you choose the card choose two tribute choose the monster you want two tribute summon and summon it
Double Summon allows you to have an extra Normal Summon. This Normal Summon is no different to your usual once-per turn Normal Summon. If you've got two monsters to tribute, then sure, you can tribute them for an 8-star monster.
No, because it wasn't 'properly' special summoned. To be able to special summon a Ritual Monster from the graveyard, it has to be initially summoned by Ritual Summon. Ritual Foregone does not Ritual Summon.
Yes, it does have to be in your hand.
No, it's not true. You get only one 'Normal Summon' per turn, but not only can other cards 'Special Summon' one or more monsters in the same turn as you do this, but other cards can let you Normal Summon more than once too.
A tribute summon is a form of Normal Summon. So that means you can only tribute summon OR normal summon ONCE per turn.
Yes, you can use the trap card Ultimate Offering which you would have to pay 500 lifepoints for each extra normal summon, or there is a spell card called Double Summon which allows 2 normal summons.
Special summon Quickdraw Synchron discarding Level Eater, special summon Level Eater from the graveyard, then sync them. Level Eater -- 1 star If this card is in the Graveyard, you can activate its effect by selecting 1 face-up Level 5 or higher monster you control. Reduce that monster's Level by 1. Special Summon this card from the Graveyard. This card cannot be Tributed except for a Tribute Summon. Quickdraw Synchron -- 5 star You can send 1 monster from your hand to the Graveyard and Special Summon this card from your hand. You can substitute this card for any 1 "Synchron" Tuner for a Synchro Summon. This card cannot be used as a Synchro Material Monster, except for the Synchro Summon of a monster that lists a "Synchron" monster as a Tuner monster.
No one card can Special Summon any Fusion Monster. Because some Fusion Monsters specify that they "cannot be Special Summoned except by a Fusion Summon", cards like "Metamorphosis" will not be able to Special Summon them. Even "Instant Fusion" cannot Special Summon Fusion Monsters that state "This card can only be Special Summoned from your Extra Deck by returning the above cards you control to the Deck."
The only time you can do this is if you are tributing the monster for a tribute summon, or sending them for some kind of special summon, like for Destiny Hero Plasma or a Synchro Summon. But if you wanted to summon another Lv4 monster, you cannot simply make room by sending a monster from the field to the graveyard, you can only do so by effect or game mechanic, like when it is destroyed by battle.
Since White Stone of Legend is a tuner it can be used with any other monster to synchro summon that is allowed
Mausoleum of the Emperoer allows you to pay 1000 life points per monster needed for the tribute, however currently there are no Lv12 monsters you can Normal Summon. Most are Fusion or Synchro Monsters, the four that are plain Effect Monsters all say they cannot be Normal Summoned or Set.
When using metamorphosis the LV of the Fusion monster should be the same as the LV of the monster you are going to tribute.