No, not exactly to make an egg grow faster in platinum you need a Pokemon with the ability either Flame Body or Magma Armor. Those abilities split your steps in half.
Flame Body-Magmar (you can find at Fuego Ironworks)
Magma Armor-Slugma, or Magcargo
You can't get eggs faster but you can hatch them faster by having a Pokemon that has the Flame Body ability.
It depends on what Pokemon you have in the daycare. The Pokemon that hatches from the eggs given to you by the daycare man will be the pre-evolved form of the female Pokemon you have in the daycare.
Yes.
No it wont but if you have the Cheat Instint egg in daycare for action replay then yes
put a ditto in the daycare with another Pokemon
you can't give eggs to the daycare lady, only Pokemon
Because your Pokemon are still in the daycare. If the two like each other, they will keep making eggs. Take them out of the daycare if you do not want any more eggs. If you do not, they will not stop.
put it in daycare with another serperior or a ditto any level
pokemon make them its ovious
Put it in the daycare with a ditto
Evee + Ditto in daycare
If you mean can you get eggs of your Pokemon from her, then yes