Dear @Hsan,
Welcome to the Wefugees Community and thank you for reaching out to us.
Your questions are indeed a bit complicated but I tried to make some research. My first thought was, that the airline most probably wouldn't let you board in case you can not show a requested transit visa. Then, I checked the German Federal Foreign Office's Website where I read that only five airports in Germany have an international Transit Area enabling you to transit without formally entering the Schengen area and Frankfurt is one of them. The website also gives a list of countries of which its nationals do NOT have the transit privilege and subsequently need a transit visa - but Tunisia was not listed here. From what I understand, you therefore may not need a transit visa in the first place.
For more information on applying for asylum at the Frankfurt Airport please see this thread, for instance.
However, I do not understand how it could be possible to board a flight to Sweden (as final destination) without having a visa - this would not work I guess (for several reasons - the Dublin regulation one of them).
I am sorry that I can not give you more positive information for now. Nevertheless, I will also link my dear colleague @mbeon-fardeen here. Maybe he can correct me if needed or add some advice.
In any case, please also don't hesitate to get back to us with any further questions. If it's about the same topic, please use the comment function in this thread.
All the best,
Meike
PS: I saw that you opened a second thread with similar content. In order to keep a better overview and information in one place, I will close that one. I hope this is okay for you.