1

Just back from first trip to Tunisia .... no problems encountered. Safe and possible to travel easily. Trains cheap and good, Louages good and probably no more expensive. Even taxis are cheap compared to europe, but always make sure the meter is running. Just remember that many parts of Tunisia are very poor and there are many unemployed, so tip people (in dinars) when you can! We didn't go to many of the 'sites' you mention but there aren't many tourists in Tunisia so there won't be any queues!

Have a great trip. Take a copy of Lonely Planet as it is very helpful even though it was published pre Revolution

2

We are in Tataouine right now.
We had been travelling by louage and its pretty good: cheap-fast-funny.
No problems by the moment. Its really peaceful and empty of tourists.
Today we have visited the ksars near Tataouine and we have seen just a pair of couples of tourists.
En joy your trip.

3

Yes, I've also been backpacking 9 days in Northern Tunisia last February. No problem.