I hate to ditch the phoenix as it is currently the only damage dealing off element creature we have, I'll work on getting a good deck going. I can pretty much do anything when it comes to phoenixes. Just gimme an hour.
Also, What if we keep 2x Heal and 5x Adren? That way it's not overkill on life cards but we still have the ability to heal a bit.
And no, you can convert any cards but only to YOUR element as a Pillar or Pendulum.
As a new rule in War #2, teams now have the option to convert some of their cards. This means that they can replace any card in their Vault with a Pillar or a Pendulum of their element. Converting helps teams to avoid a situation where they would be otherwise forced to build "suicide" decks. Converting will be done by the Vault Organizer who posts on the Vault topic which cards are converted, and then editing the Vault. Teams can convert a maximum of 12 cards per round.
EDIT: After testing with earth, the Golems do not seem like such a good idea. I think what you originally had is probably the best.