Hi!,
As you are only there for a short while, have a look at http://www.daytrippergoa.com and view their 'Panjim City & River Cruise'. It's an afternoon and evening trip - for £6 each you can't go wrong!

As for munchies, have a look a Javalin's trip report. As a recent 'returnee' those recomendations are bang up to date... Don't forget to come back on here and tell everyone how you got on!

If you must have Indian cuisine try Ritz Classic Hotel, 18th June Road, Panaji. It's a favourite with the locals and is always busy at lunchtimes.
Have a look at the review here.

My personal favourite in Panjim is - A Ferradura (Horseshoe) Ourem Road, Panaji. It's a bit more sophisticated and the food has a more portuguese influence.
Have a look at review here.

Don't leave Panaji without a visit to the Hotel Venité, 31st January Road, Panaji. It specialises in seafood and has delightful little balconies with wonky little tables only just big enough for two - lots of room inside. It's up a little street in the Portuguese quarter - don't be put off by the look of the place.
Have a look at the review here.

Hotel Venité

Thanks guys for the suggestions. I guess I got enough for a short trip. Will visit all the four eateries.