There are a few nightclubs in PEK and Sousse - Bora Bora and Bonapartes come to mind though I've never been as they're not my scene, and some of the hotels also have their own nightclub. The safari trip is good though not relaxing as there is a lot of sitting on the coach. You can usually do a 2 or 3 day trip and can find a whole lot about it elsewhere on here. The rep at your hotel will often have it on offer but I booked it locally with a company called Saphir Voyages who were excellent. There are some nice restaurants around at various prices. A new one in Sousse is called Vintage, a restaurant/bar just opened by a couple of French men, Eric being the chef and singer. It's just past the Marabout in Sousse. Not one of the cheaper places but beautiful food, excellent service and a nice atmosphere.
Most cafes have their price lists posted outside and, unlike Marlou, I've always been offered a menu . I've also never had a problem with the shopkeepers, not even in the Medina in Sousse. They obviously try to get you to buy and inflate their prices for the tourists but ,as long as you realise that, you should be able to 'negotiate' a good price for most things. A good buy for ladies are the beautiful pashminas. They usually start off at about 30 dinars but I've never paid more than 10.
You can get the train or metro from Sousse if you want to explore on your own, such as Tunis or Sidi Bou Said. You can also take a louage (shared taxi) which will get you to most places. Train, metro and bus fares are dirt cheap but with ordinary taxis you need to either insist they put the meter on or 'negotiate' a price before you get in - don't pay more than 7 dinars from PEK to Sousse.