How bad are pre work outs like nitric oxide for your body, for example super pump 250?

Depends. Most pre work out drinks have two main purposes and that is to prepare your muscles for the workout and to give you a boost of energy to complete your workout. Keeping that in mind there are many pre workout drinks out there with a vast array of ingredients claiming to give you an edge. What ever drink you choose make sure you drink plenty of water both during and after your workout.
Bad for Some. Have a look at the link below...It will show you the ingredients in sp 250. Do note, however, that you (unlike other folks) may be unusually sensitive..Or even allergic...To some of these ingredients. Caffeine, amino acids, vitamins and minerals are only part of the story! http://www.Bodybuilding.Com/store/gn/superpump-max.Html.