They are indeed Hindus and really we have no idea how devout they are as there aren't any obvious signs as there would be with Muslims such as abstaining from Alcohol. It's like a lot of viewers assume Dev in Corrie is a lapsed Muslim because he drinks but actually he is Hindu so he is allowed to.
That said, I don't think that any of them have had Hindu wedding services, just civil ones which might indicate that they aren't devout. Priya did have one planned with Rakesh but it was called off at the last minute.
As it happens, there is no specific banning of eating any specific animals in Hinduism (unlike Judaism or Islam) but non violence to all animals is central to the faith and for that reason, many Hindus choose to eat a vegetarian diet so no animal has to be killed for their diet. But it is an individual choice rather than a commandment.