I just want to know.....
Of Course! I Didnt Use Giratina in my Platinum! I Beat it:)
It Is Easier with Ho-oh, but beatable without:) Hope This helps!:)
Yes, it's not a problem, at least you see it to complete the Pokedex!
Yes but you must at least encounter him and defeat him
though I would suggest catching him he is a very
powerful pokemon with a move that has a 50% chance
of burning sacred fire.
Yes I restarted my game but I passed it without ho oh and now I have it it isnt very good though