Is this a good team?

Almost, drop Barbara for a pyro or electro. Preferably one that does off field pyro damage like Durin, Mav, or Xiangling.

Almost, but Barbara ruins the team by ruining Chevreuse's passive.

Boot her and and slot in a pyro character.

the team would be better with 3 characters and dropping Barbara. It's a rare instance where 3 characters would be better than 4.

fine for overworld (especially if chevreuse is c6), since having only electro for pyro shields can be a bit painful, but you're probably better off using an electro or pyro character e.g. bennett or fischl instead of barbara

If Chev is C6 drop Barbara for literally any off field pyro applicator like Mavuika, durin, or even xiangling

remove barbara and put on someone like Durin, Mavuika, Xiangling, Pyro Traveler, or maybe Benny if you are okay with Circle Impact