He's probably scared. Give him some space and come back and see him a little later :)
You should definitely take it straight to a vet!
It depends how cold it is. If you can go outside in a short sleeve shirt and not be cold, it is probably OK for your guinea pig. If it's very cold though, don't take the guinea pig out...even in a blanket!
You can feed them both guinea pig food. Don't feed the guinea pig the rabbit food or it will be sick. Rabbits are ok on guinea pig food.
No it isn't ok. Guinea PIg food is made for Guinea Pigs. Your Cavy will get sick if they do eat hamser food.
Yes, tomatoes are great for guinea pigs.
No. It is not ok to have them in the same cage, as rabbits have very strong legs, and can very easily kick a guinea pig and kill it.
When I got my guinea pig, we didn't know she was pregnant, so about a month later, my sister got one that wasn't pregnant. It was a little less that a month after that that my guinea pig had 2 babies. During that time, though, Molly, the pregnant guinea pig, was acting very territorial, and Milly, the non pregnant guinea pig, was staying by herself and not having anything to do with Molly. So make sure that if you put a pregnant guinea pig with a non pregnant guinea pig, that the non pregnant guinea pig is a girl, or else there WILL be trouble.
yes its ok to give your pig grains but try not to give it too many.
Yes
Not if a guinea-pig eats it, as you have put in the question. It's okay if a guinea-pig chews a piece of fabric, because it will grind their teeth down, which is a good thing.
It depends. They certainly wont be aggresive, but if you do, make sure to spay and nueter them.
no if you feed them it, they have 99% of dieing