im not lazy feeding either I just didnt know, we all have to start somewhere & the shop assistant sisnt tell me to feed him anything different so how am I supposed to know otherwise.!!!!
Calm down; I had the winking smiley face to show I meant it gently or in jest. And while we all have to start off somewhere, you should do some reading before you get a fish so you're aware of at least what its basic dietary needs are.
Out of curiosity, how has Seth behaved with the guppies? There's a poll right now about mixing the two species, since they'll often fight. If he is stressed by their presence, it could be another reason for why he's not eating, though usually the bettas are the ones
causing the stress
As for that's in the pellets? Oh, a variety of meat byproducts, fish meal, and other things that sound completely gross. But, what's important is that they are specially formulated not just for carnivores, but specifically for bettas. In regards to the question about will it be ok if your other fish eat it, I'm sure it wouldn't hurt, but I'd be careful about how much they're taking in. As AlexDaddy mentioned, high-protein foods can cause constipation in some species. I'm not too sure of the kinds you have, but if any are herbivores or omnivores, the protein load in the pellets might be a little much for them to have a large amount of.
edit: I just looked at the tank, and thought I'd suggest something in case stress is his reason for not eating (though as Alex Daddy said, he may just be getting used to the tank). From what I can see, there's the two caves, but not much plant cover. Since bettas are kindof solitary, if other fish are in those caves, he might be disinclined to go in there to hide, even if he really needs too. Maybe you could get him some silk plants to hide and rest in. Most bettas love them ^^