It all depends what you want.
When we went last December, there was so much we wanted to do but we ran out of time.
Kerala isn't in Goa. It's a different province. You must remember, India is a large sub continent. It would be a journey of about 400 miles each way - slightly further than going to Mumbai.
There are thousands of eating places. Depends where you're staying in Goa. Most have good cheap Indian food plus many other nationalities.
We found a good one we liked and frequented it often.
We also found the places we liked the best for eating were at the markets - the night market at Calangute (definitely worth a visit), where we shared a really cheap korma, and the day market at Anjuna where we ate with the taxi drivers on a fish curry for a few pence.
Everything 8is cheap but if you want really cheap, authentic travel and don't mind uncomfortable crush, the local buses are an experience in themselves. Motor rickshaws (tuk-tuks) are cheaper than taxis. taxis outside hotels are more expensive than you'll find by walking a hundred yards down the road.