Do trainers just stand there all day, everyday, just waiting for you to ask them for a battle? Wow their lives must be boring.
They're either on a journey just like you, in which case you (the player) also have no life, or they decide to sit out on the weekends and battle then go home for bed.
Why are there young children in the Battle Facilities, with perfect Pokemon and great strategies?
Like you, they trained.
Why can't a Pokemon just eat the freaking Salac Berry at the start of the battle?
League rules?
How does an epic battle with Kyogre vs. Groudon last more than a few mins? Kyogre has the type advantage and deals alot more damage. The only chance Groudon stands is SolarBeam.
They're both titans. They don't have types. They represent Water and Ground respectably, but are beyond that.
Why do those pudgy guys in blue always stand infront a cave entrance? There's at least one in every region, and how do they know when you've obtained the National Dex?
They're probably authority figures put in place by either the League or Oak. Like one of Oak's many aides.
Why do so many people look completely identical? You, along with other main characters, seem to be the only ones different.
Space. And time. You try designing several hundred individual trainers per game... Better to just make trainer classes and call it a day.
Porygon-Z? What happened to #3 - 9, A - Y? Not to mention various combinations.
The Z denotes it as a glitch evolution (upgrade) since Z typically has a strange connotation. It may also suggest there won't be any more Porygons (Z being the last letter and all).
What's up with the spoons, Alakazam?
As per the Dex entries, the spoons are physical representations of Alakazams' psychic power. They don't really exist, or do on a purely tangential level.
Why does Eevee evolve into so many different things... "Gen 5! Dracion, Spookeon, and Beetleon! Exciting!"
Its Dex entries variously say it has an "irregular" or "unstable" genetic makeup. Works for me. (Though I'd argue that Leafeon and Glaceon are just bad ideas)
Why isn't there a TV Rotom?
Because Rotom is already Electric type, so it'd be fairly redundant. However, there's always the possibility for the future.
Read Pincir's Pt Pokedex entry... ???
What? It breaks Pokemon in half? I imagine it does this in the wild, but owned Pokemon have their strength held back by their trainers.
Oh, and how do Slugma sleep (while contantly moving, to avoid turning into a rock) ?
Maybe it doesn't sleep. Or it sleeps but keeps its body on cruise control... Or it's like a shark.