Excuse my lack of accented e's.
Definitely w/ Aqua & Star on placing emphasis on exploration, as well as the roleplay having a separate identity from the games.
Important for me, too, is developing the setting. There should be world-building on the GM's behalf. Pokemon doesn't have much of a consistent lore regarding how Pokemon are actually integrated in society, and then how humans conduct themselves on top of that: social expectations, work force, government, education, etc. Obviously, people can make up how their characters got educated and at what age, but when certain aspects of the world aren't constant, individual players will bring in separate interpretations of the Pokemon world.
This is a very good point, and the type of setting you create and the social rules you embrace will help set the tone of the adventure. Tone is very important to establish early on, and it gives players an idea of what they may be in for. I'm not saying that a darker tone is better, because that's not always true. However, I always found that some sort of peril helped keep me on my toes and made things more realistic and more interesting. Unless you're running an RP for younger crowds, being completely immune to any lasting negative effects makes things a lot less engaging.
This has occurred in pretty much... every journey I've participated in. The worst result is that meaningful interactions between player-controlled characters is practically nullified, and characters feel paper-thin. No one has individual lives; their existence as characters is in-the-moment because that's the only aspect established! There's nothing for them to talk about because there's no real setting. There's no such thing as "life experiences" that have molded who the characters are today; characters have history, but it's without a foundation, and thus is without impact.
I know what you mean; it's like the NPCs were place there just to serve a tiny purpose, and nothing more. They have no ambitions, fears, hopes, or anything beyond helping/hindering the main cast. Flat villains are the absolute worst for this, and in a genre where evil teams are everywhere, having an uninspired one hurts the story a lot. This is even more true if a big part of the adventure hinges on ruining their operations and taking them down.
It's common knowledge that setting is important in fantasy 'verses, and this should be applied to Pokemon roleplays too. And I adore world-building in the Pokemon 'verse because things are so vague and unexplored; you can do anything. Creating an opportunity for that would make for a fantastic roleplay!
I think this is a huge draw for the creative fandom in general; you can make almost any type of character and have some control over the setting, but without the need to make something from scratch. I can be a chaotic good Ranger helping after an ebil team left the region half-destroyed. I can also be a research assistant, going on a journey to find where the regional Prof. is, as they vanished months ago without a trace. Or, I could take the role of a shy, meek character who wishes to become a top co-ordinator, but who freezes the second they step on the stage. Giving the RPers some choice in what their characters choose to pursue is another thing I'd recommend.
(And since the common consensus is your character gets a 'starter' for these types of RP's:) The less limitations on starters, the better, and I personally hate restricting the starters to the Grass/Fire/Water ones from the games.
Totally agree. Heck, in the manga, many of the protagonists have non-starter Pok?mon before meeting with the regional Prof. and getting their dex. It does give more room for creativity as well.