Pokémon battling is NOT animal abuse. Pokémon are powerful and enjoy battling, and they can be healed easily. However, there is an evil team that does treat Pokémon inhumanely.
There are multiple spider Pokémon. Two of them are fairly large, and one resembles a tarantula. None of them have eight legs so far, though there are two eight-legged spider Pokémon that will be added in the future.
In the game, YOU are meant to be the Pokemon trainer. The three team captains and various Rocket trainers will look directly at you on screen and address you by your trainer name.