There are two Small Keys in the dungeon, so yes, you can get two keys. Both keys are required to get the Lens of Truth.
Master keys open all rooms in a building. Grand Master keys open all rooms in several buildings.
By planing and winning the Key Quest game
They are free tail keys
you cant because in every dungen there is enough keys for you to get through
If you mean the gold keys then you have to collect a lot of rupees in the 3 main stages
about three or four
No, not all Master Lock keys are identical. Each lock is typically assigned a unique key that is specific to that lock.
all of the top and bottom keys plus the key right under the bottom three keys
There are 6 Small Keys and the Boss Key. Don't worry about running out of keys - if it seems like you have, there will always be an extra key that you can find. The compass will show you the location of all keys in the dungeon.
Lock cylinders can be designed in a series so that one "master" key will open them all, but their individual keys will not open each other. Some manufacturers release sets of master keys to locksmiths, that can be tried on locks in the hope that one will fit. There is no single master key that will open all locks of a given make.
The four corners of the map
When you become a member, each month that you are a member, goto the Twilly in Battleon , click on "treasure chest?" button, then click the "FREE Magic Keys" button and a member only quest will pop up. Accept the quests, and turn it in. There are no quest items needed for the quest, so once you accept it, you can turn it in right away. 2 Free Magic Keys will drop. The keys are non member and acs, so you can store them in the bank unless you need them or until next month. The keys do stack.