Single Class 

 Yes

 Yes- applicant can claim priority of up to 3 months as per the convention

 addition

1. Power of Attorney simply signed ( to be witness by two)  
2. Date of use in Sri Lanka (if any)
3. Certified copy of the priority document. 

3 months from the date of publication.  

10  years from the date of registration  

Power of Attorney simply signed. 

None due

N/A

A mark becomes vulnerable to an action for cancellation if it not been used in the preceding 5 years