Well to be fair, Kurama is also a grass type lmao. He's just super into Attack and Special Attack moves, and that Speed stat ain't nothin' to fuck with. Botan's gotta work on her stats too. She's like level 5. Koenma gave Kurama a level 5 Botan lmao. Botan's a grASS type ;333 lmao I'm done now xD

Bulbasaur's the shit but if we're being real, all Gen 1 starters are dope as fuck. 

A local fitness center can help with building her speed. Stamina is more important than strength right now, because Botan's not someone who will rely on physical strength a lot, at least not in the beginning. Kurama needs her stamina built, because training steadily becomes more and more rigorous, and she has to be able to endure a lot in a day because this is basically cramming in a lot of training in a short amount of time. On top of schoolwork, his training is going to leave her exhausted X.X I would say just sum up the uses her spiritual energy has with the rose like you said--and strongly consider giving her the powder and spore moves lmao come on that's funny. 

Paying Genkai a visit would probably be a weekend trip, wouldn't it? Genkai doesn't seem like she has the patience to train someone for only an hour or two a day, but maybe for Botan she'll make an exception because she's a sweetheart? Paying Yusuke a visit, since we left him there for training, would also be a nice additional cameo.