Having more than 8 badges

I recently started playing around with pokemon essentials and I've been wondering is it possible to have more then 8 badges? My idea is to have a gym focusing on each type of pokemon with there own individual badge so that the player can have a bit more variety and not fight the same gym leaders over and over again.

yes u can have over 8 gyms badges

Is there a tutorial or something on adding more then 8 badges? Is it possible to raise trainer levels based on the number of badges a player has.

It is possible. There isn't a limit of 8 badges in Essential: http://pokemonessentials.wikia.com/wiki/Pokémon_Gym

I just don't know what to do for the trainer card, to display the new ones. I never looked at the code here.

Does my idea seem interesting from the standpoint of the player? My end goal for this a game where the player can pick and choose the gyms they want to go to. Everything from a dark gym to a fairy gym players only need eight of the eighteen badges to access the elite four but the more badges they get beyond that will unlock special areas and harder battles.

Could be interesting. But you need to give players good reasons to do more gyms. New Pokemons, new items, I don't know...

Pokemon Navy allows you to skip gyms. You should talk with the creator to see how he did it.