1. Are the limits on what sails we can bring (1 main, 2 jib, 2 spinnaker) the identical sails for the entire week, or can we switch sails each day for example on a windy day, to protect a good sail, can I bring out an old sail to protect my only good set of sails?
2. How is the around block island race, the same or different from the above?
3. I have a code zero on the boat, is that allowed and or useful for around block island?
I'm sure the class measurer will confirm this, but rule 5.3 applies:
5.3 Sails carried on board and used for J/109 Class or fleet sanctioned events for inshore buoy racing shall be limited to five sails: one Class mainsail, two Class jibs, and two Class spinnakers. Each Class sail shall comply without exception with the provisions of these Rules. A jib or spinnaker may be changed for the other declared sail at any time during the event, at the discretion of the captain.
In regards to your question 1 - you are limited to 5 sails total, unless a sail is destroyed during the regatta beyond repair, in which case you need to ask permission for a substitute sail.
The around BI race is part of the series - same sail rules apply.
The Code Zero, if it measures in as a spinnaker (mine does) may be used. However, this is one of your two allowed spinnakers and no bob stay is allowed. I would recommend a medium light class spinnaker and a heavy air spinnaker instead, but you may pick and choose as you desire.
If you damage one of the 5 declared sails beyond repair you can ask the Class Measurer for permission to replace it with another registered and approved sail, that sail must then be used for rest of the regatta.
As far as a code zero it can be used as one of the two spinnakers if it is measured, approved and declared as a spinnaker.
Under NO circumstances will it be allowed to use the Bob-Stay, 5.3.16