1:My first idea is pixelmon spawners/ spawn eggs. These in my opinion would be used for creative, so if some one wanted a sertant pixelmon to spawn in a sertant place in their adventure map, this is what they would use to do that.
2:My second idea would be to have pokemon spawn in your would with the same level (or a little higher) as either your weakest or strongest pokemon, that way your pokemon don't faint 24/7 to a level 42 pokemon, when your pokemon is only level 5-30, to me this would make it some what easier for people to level up their pokemon (same thing for trainers.). Although this might be too hard to do for servers.
3:My final idea would be to make it so you can edit a trainer and how it works on creative mode, maybe you could have an object only obtainable in creative. This would mainly be use for adventure map makers to edit what pokemon and what level pokemon they have, there should also be a setting if it will do what trainers do in GBA pokemon, like stop you and make you battle them.
If you read this I hope you agree, I also hope you took consideration while reading this, as always thank you, and have a good day!