Assalaamu alaikum sister Diane
Firstly mubarek ( congratulations) on your shahadah!

Alhamdulillah
I am not Tunisian but my husband and I visited Tunisia in May this year ( Hammamet and surrounding areas) Its a very beuatiful country. We went to the large mosque just outside Tunis ( on the way to Sidi Bou Said? Cant remember the name of it sorry) and we were allowed in even though it wasnt time for scheduled prayer. There was a guard outside but he only seemed to be there to control tourists - he didnt blink at us going in ( 2 ladies in hijab, 2 men and a baby) and we were free to walk around. I did see him stop a lady ( tourist) who wanted to go in because she wasnt wearing anything to cover her hair but that seemed to be all he was there for - there werent any other restrictions.
Having said this it was only 1 mosque- smaller ones in more rural areas maybe different I dont know, though I doubt it cos I can see no reason for the govt to restrict people going in there - most mosques have some sort of guard/security/caretaker and of course an Imam who keeps an eye on things
Derspite this we did speak to a practicing Muslim brother in a market and he did inform me that those who openly practice Islam are watched. They seem to take particular dislike to the beard on men....went we were in a taxi we got stopped many times and when we asked the locals why they told us it was because my husband and his friend had beards...
The thing you have to understand about Tunisia I think is that it IS a muslim country but the government is largely secular and many Tunisians are not practicing Muslims. Because Tunisia's economy is largely dependent on toursim, it of course is acccomodating to non muslims in every way - you can buy alcohol, tourists are advice to dress apppropriately but many dont' - many Tunisian women dont either...but when you speak to the local people they are all trying their best to practice Islam - its just they do it in private since they dont want to be seen to be opposing the secular government - even if they are not - because it can make their life difficult.
Tunsia went through a period of time not so long ago whereby they were ruled by someone ( cant rememebr his last name sorry) who opposed Islam in favour of some secular practicies...this gave many Tunsians a bad idea of Islam though lack of education. While some of his ruling opposed Islam, his government replenished the economy of Tunisia so to some people it made 'life better'. However in reality, they lost Islam and it is only since his death ( 2/3 years ago) that they have begun to recapture Islam and practice their religion again.
The country is growing in terms of economy and Islam and the Tunisian people want Islam back again whereby they do not have to worry about praciticing openly. More mosques are being built, more men are beginning to have a beard, more women ( young women) are starting to wear hijab and they are educarting their community back to Islam. We visited some friends, a muslim family, and they were practicing - they lived just like any other muslims and they were the most generous hospitable people I've ever met.
Anyway - as I said - I am not Tunisian, we learnt this only in the time we were there so take it with a pinch of salt..and most importantly DONT be put off Islam by it - its an issue whereby the people were temtped by and trying to accomodate tourism to support their economy but they are still Muslim anf the country is still Muslim.. Muslims are not perfect ( any of us, Tunisian or other wise) Islam IS perfect. People are also individuals, including Muslims, and subject to whims and desires like any other person - so alot of what I have said here, please remember is generalisation.
Hope that helps in some way. May Allah swt bless and guide us all, Ameen
Wasalaams