Can Floette Eternal be obtained by glitches or hack-only

Zap plate and Magnet are the same boost. Any two items that read with the same effect generally have identical effects; the reason they differ are because they have different effects on different Pokemon, usually one is an evolution item for a specific pokemon. In the case of the elemental Plates, they are actually items for Arceus to hold, they change his form and typing due to his Ability, Multitype. The Plates are probably included because there's so many it wouldn't be practical to give them all out when they eventually distribute Arceus in a gen 6 event.

It is currently unknown what tipping does, and taking photos gives you items, but doesn't affect the shiny rate. The only known ways to increase the shiny chance are:

• Breeding with a pokemon from a different region. (The Masuda method)
• Chaining via the PokeRadar.
• Chain fishing
• Obtaining the "Shiny Charm", which is a key item obtained by catching one of every non-event pokemon.

Sources: http://bulbapedia.bulbagarden.net/wiki/Photo#Pok.C3.A9mon_X_and_Y (photos) http://bulbapedia.bulbagarden.net/wiki/Shiny_Pok%C3%A9mon#Generation_VI (shiny methods)