Don't spam the suggestions sections please. Try to combine all the suggestions into 1 thread and continue that always because flooding this section in a short span of time is not encouraged and useless too.
that's what the PC is for. you can only carry six pokémon with you at a time. this is not a new concept, it's how pokémon has been since original red/green.
i don't know how choice items would even be implemented into a pvp system like the one rise has. recoil damage isn't a thing currently, so life orbs are also not likely to exist any time soon.