Does having both parent Pokémon, of the same species and with Hidden Abilities, increase the chances of getting a baby Pokémon that has said Hidden Abilities?
No. Whilst both Male and Female Pokémon have a chance to pass on their Hidden ability in Gen 6, Male Pokemon will only have this chance to pass it on when breeding with Ditto. When breeding with the same species, only the Female's Hidden Ability matters.
Is having a gender specific Pokémon a deciding factor if the egg would be a male or female variant?
No, each Pokemon type has a specific ratio to be a specific Gender. The most common is a 50/50 chance to be either Gender (which your Ralts has):
There are also Pokemon that have more skewed results toward a specific gender. Eevee for example, has an 87.5% chance to be Male. There are also Pokemon that are always one Gender like Kangaskhan, and Pokemon that are Genderless, like Metagross. (These must be bred with Ditto, they cannot reproduce with a member of the same species).
You should have a look at Bulbapedia's Breeding Guide, as it covers a lot of ground about Egg groups, getting Egg Moves, Hidden Abilities, IVs and other useful info.