You will be welcome in Tunisia !!!
I guess you'll stay some days in the area of Monastir and Sousse and why not going for a tour in the south or in the cape bon !!!
Concerning MIR,i know you will enjoy spotting there !!!
You will find almost all the European charter operators as well as the Tunisian air carriers !!!
Spotting itself is legal,especially for you tourists !!!
If you want,you can ask the police at your arrival,and in general there is no special restrictions !!!
I'm not talking about myself here who had a bad experience six months ago.I had only a pair of binoculars.
If you want,you can contact me and we spend the spotting days together !!!
If we won't meet,of course you'll see me approaching or taxiing for 25 or 07 !!!