I understand the resentment of many posters in this thread, however, like I wrote, bezness is a very different thing when the usual "Man" is a "Woman". Only a very good observation and understanding of the social life (I am reluctant to say "culture", because, in reality, I don't see it as relevant) will help to tackle this issue.
I have been there and seen it, done it - all of the things the thread starter writes about. Me and my wife are now married for almost 15 years. My contribution to this thread is in reminiscence of what I have personally experienced ... but then again, at this point in time I had lived in Tunisia multiple years already which made the "adventure" more of a calculated risk. Before our actual marriage, we had been with each other for around 40 days (meeting in person), altogether about 2 years.
She got a university education (better than mine) and she earns good money (more than me). She comes from a quite conservative rural family (and never talked to anyone not from Tunisia before she met me), but for me, there was never a question of becoming muslim. I have been, am, and will be atheist for the remainder of my life (and so will she). So all the "cultural" things around marriage (hammam, hairdresser, harcous, rural wedding) was a nice-to-see folklore, but nothing more. And we actually did not even marry in Tunisia, but on the second day of a "90 day fiance visa" (a marriage in Tunisia would have had only disadvantages for me and my wife). We did, though, have a wedding party nevertheless (we had to pretend we were married or else her father would not have allowed her to get on the airplane).
So, what we did, was this: I called the embassy and laid out the problem. They were sympathetic and we got a date. At that time, we drove to the embassy and were let in (her father had to wait in the car, because "only we 2 could get into it"). We met the consul, had a drink with him and after 20 minutes, we left the embassy ... and pretended to be married now. The next day was the wedding party and from the wedding party we drove straight to the airport and left Tunisia for good.
The whole process was fairly easy, as in getting the required documents etc. The real problem was to arrange (weeks before) everything into a tight time frame (visa, alleged marriage, wedding party, tickets, marriage date, etc.), but it worked out pretty well.
Today, my wife has 2 passports, the toy passport of tunisia with her birthname and a "real" passport with a "new" first and last name (by naturalization). She visits Tunisia only to meet her parents and siblings, like every two years, (and when I accompany her, I usually stay in the tourist regions and come to visit for a day or two ... what would I talk with the parents about, plus, we speak different languages), nevertheless, I am a respected member of her family (probably because we cannot really talk to each other

and I respect all of them, too).
We don't bring money to Tunisia (we have never been asked to), except for the costs of our staying there and some low-cost gifts and we wouldn't help people to get out of Tunisia (we have never been asked to). In a case of a real emergency, we would send money, but not to enable someone prowling around just because they have family members living abroad.
We do not invest any money in Tunisia either, because our life is not in Tunisia - and never will be.
Interestingly, we did not meet in person at the beginning of our relationship. It was rather a blind date, because I was just driving around in a taxi and got a telephone call from someone allegedly expecting "Ahmed" to answer it. As it turned out, my future wife got my number from another woman - and we met then for the first time after 2 weeks of this initial call.
Anyway, I thought it might be interesting to hear such a story also. I didn't write about all the knicks and knacks of the whole process, but without a profound knowledge of the tunisia social life, I would not have been able to achieve this. Of course, one needs the right woman for this as well, and, once again, the knowledge of tunisian social life helped a lot in that.
Finally, as can be seen from this story, a well-founded relationship with a tunisian person has a lot to do with time and money (and honestly, also school and general education).
As a serious advice: Those, who won't be willing to spend this, especially the former, rather have a look for a partner of your own "culture". You will be better off in the long run ... and you will save a lot of money (and time) - and headache!