Yes 

Yes

Absolute novelty is required

It is possible for granted and published patents in the Official Gazette to be searched by their corresponding patent number, title, and patentee name. 

Yes, a translation into French or English is required

1. Power of attorney, simply signed. 
2. 3 copies of the specifications in either English or French. 
3. 3 sets of drawings. 
4. Deed of assignment from the inventor(s), legalized. 
5. Copy of the priority document, if priority is claimed, certified with English translation. 

Items 2 and 3 must be submitted at the time of filing. Documents 1, 4, and 5 may be submitted within 60 days from notification date. 

Regarding PCT applications, the international preliminary report as well as the publication sheet showing Tunisia among the designated states must be submitted.

20 years starting from the filing date. 

A maintenance fee is due annually on the anniversary of the filing date.