Welcome to Gaia! ::

I want to know if the way I have my party set up is a good idea. I'm still not that far into Gran Pulse, so I can switch out if needed.

Leader: Hope

It may seem stupid to have Hope as the leader of the party, given his pitiful HP, but the main perk of using him is to choose which buffs to cast, since when facing poisonous enemies, the computer, as revealed by auto casts, would rather choose veil. Also, since Lightning and Hope use physical attacks, Hope's long range attacks help. I compensate for Hope's low hp for bangle items, which brings it up to par with the average character. Theoretically, I could switch out Hope for Vanille if I wanted to trade Hope's Synergist role for Vanille's Saboteur role.

Snow

Despite the fact the Snow's ravager role is nearly useless due to his limited element choices (while Fang learns all the elemental strike spells), and the fact that Fang has the saboteur, I decided to use Snow, and Fang's higher attack, I chose Snow. The reason is that Snow has significantly more HP, which makes him a better sentinel in terms of survivability. I equipped him with an Aurora Scarf, to make sure he could distract foes before a hard hitting enemy kills Hope.

Lightning

I use a physical setup for Lightning, with a physical weapon.
She typically operates as a commando when Snow is a sentinel, and a Ravager, using the elemental strike spells when he is a commando. During the beginning of the battle, I use her as a medic when Snow is defending and Hope is buffing. Theoretically, with enough investment in Ravager, Fang could fill this role nicely due to her higher attack stat and also learning the elemental strikes, and the saboteur role would compliment Hope's synergist role, although Lightning's developed medic role would be missed.

---
So anyways, is my party good, or should I switch out someone?

It sounds all right. My party is the same only I do use Fang instead of Snow (I don't like the idea of not having any Saboteur) and Lightning is my leader. It would be nice to be able to choose my buffs, but I don't actually use his Synergist...ness... most of the time, so it's no big deal. I find it more important to control my Medic (which is still Hope half the time, but Lightning just as often), because the AI doesn't prioritize reviving. I also like controlling Lightning because when she goes Commando (*giggle*) I spam Ruinga. A lot.

In the end, though, it's really just what works best for your playing style. If you're not having any trouble winning battles with your party, then by all means keep it. If you're not, just keep track in your head of what goes wrong: if you could've won by using a Saboteur, or if Hope is still dying before everyone else, or what have you. If that's the case, you might need to make a change.