Heh there. My first question would be where are you staying? If it's the Crowne Plaza - you will be literally in the middle of a six lane highway (they are the busiest in Europe in that part of town). Getting anywhere in Antwerp is easy either in a cab, on the tram ( 4 euro will take you anywhere - you pay the driver but don't expect a conversation in English) or on foot. Get a map of the town centre from your hotel, makes it easier to get your bearings, they will mark out the tram stops and number for you, especially as all the street names are very similar in places. Antwerp is a lovely old city that has a really laid back vibe and I find it impossible not to relax when I visit. If you ask the reception staff they will make bar recommendations and because they're Belgians and generally a nice bunch they won't steer you wrong.
If you are staying centrally in the theatre district you are within walking distance of the main square and centre of the town - Grote markt. There are literally hundreds of bars and little restaurants in the streets here. It's very difficult to eat out badly in Antwerp - I haven't managed it in 5 years. They serve the best beef I have ever had and triple fried chips.... talking of which, if you've had a bit of a night out do stop by the Frituur No 1 on Hoogestraat (loads of bars here)and have Maria the owner casually insult you and serve you chips. She's a bit gobby but the chips are immense.
If you head to the main square there are bars and cafes all around the periphery. My favourite here is t'Elfde Gebod (11th Commandment) on Torfbrug 10 near Groen Plaats in the shadow of the cathedral. It's a bar that serves food and beer (lots of beer) and has lots of religious statues stacked up on shelves all over the walls. Sounds weird but it's a good night out. Billie's beer kafateria on Kammenstraat is good too but you have to book in advance if you want to eat there. Also if you want a nice place to take clients The Square at Koningin Astridplein 7 in the Radisson Blu Astrid Hotel near Grand Central station is nice (I don't normally like hotel restaurants but this one is decent enough). For drinking you should visit The Old Arsenal or Het Oud arsenaal (head towards Graanmarkt it's on your right next to the main theatre) - follow the cobbled walkways away from the main square designed for cyclists. Down by the river there are some very foody restaurants - we went to one in the old customs house there. Lovely but expensive. Finally - you can actually have dinner at a brewery - and why not - it's Belgium - beer isn't going to get better than it is here. Huisbrouwerij 't Pakhuis at Vlaamsekaai 76, - try blonde, dark and scary beer. The place name is a bit of a mouthful but a great experience... try all the beer they make and have dinner. Hope you have a great trip. I love Antwerp. If you are flying to Mortsel airport it will cost you between 15 and 20 euros to your hotels depending on where they are. Do go in the cathedral - it's gorgeous, take a walk down by the river, sit in the main square and watch all of human life go by, visit the Zoo, go to Rubens house (Rubenshuis) located at Wapper 9-11 and Steen castle. Meir (this is a tram stop and very central also) is your best bet for shopping on Kipdorpvest. have a great time!