Re, the first question: carefully.
In all seriousness, these questions are actually more or less answered here: http://bills-pokedex.tumblr.com/post/153028583556/how-is-it-that-two-dittos-cannot-breed-two
To summarize, when in the presence of a ditto, the ditto takes on the form of the subject pokémon … only with appropriate reproductive organs. The ditto lays the egg (more often than naught), and the “genderless” pokémon (they’re actually in possession of male and female reproductive organs typically) fertilizes the egg. On their own, however, these “genderless” pokémon reproduce in a variety of ways, from fission to self-fertilization.
The latter is true for solrock and lunatone … in a way. Rather than lay eggs themselves, as genderless pokémon cannot lay eggs, they spray nearby rocks with spores, which convert the stone into a baby solrock or lunatone that is genetically identical to the parent.
(You’re welcome for that mental image, by the by.)
The Pokédex According to Bill 