Smoking on the beach (or in public areas) is apparently illegal BUT no-one takes any notice whatsoever in resort areas, don't worry about it in the slightest.
Smoking in bars and restaurants etc, IS illegal BUT very few take any notice of it whatsoever, don't worry about it in the slightest.
Smoking in public areas in Panjim etc Is illegal and seems to be enforced slightly, as I understand it a fine of 100 rps applies. Never heard of anyone being fined though.
I have walked around Panjim smoking with no problem but was asked not to smoke whilst in the crowd watching the carnival, (by a member of the public not a policeman).
.A couple of open air restaurants have places around corners etc where you can smoke "at your own risk".
I do find the ban on smoking in the open air laughable in Panjim when you can hardly breathe for the traffic fumes!
Drinking on the beach
This is something new that has been proposed to try to curtail glass/litter on the beaches etc.
I really doubt that it will have ay effect on drinking at shacks or on the sunbeds with the shacks.
Even if drinking on the sunbed is banned you will still be able to drink in the shacks,again don't worry.
The sun bed rule.., concerns the number of sunbeds that are allowed at any shack.
Invariably each season the authorities crack down and limit the number allowed, invariably each season the number creeps back up tp where it was before. It's just a kind of game they like to play.
All part of the fun
Go without any worries and enjoy.
Edited to add. Just re read your post and you are in the south, I would imagine that the rules and enforcements are the same there as in the North