Do all anti-psychotics have serious side effects?

Yes, of course: Antipsychotic medications are made to deal with serious symptoms such as hallucinations, delusions, and extreme agitation. All can cause serious side effects, which is why it's best to work with a skilled psychiatrist if you're taking them. The psychiatrist can monitor your results and adjust the dose (sometimes downwards) to your needs.

Yes: All medications have potentially serious side effects, not just psychiatric medications. In fact even things that are not prescribed including vitamins can have serious side effect if not taken appropriately. It is always a matter of weighing the benefit vs risk and you and your psychiatrist should work together to find the right medication for you.

Potentially: Many medications may have either side effects or interactions with other medications. It is smart to be aware of these. If you are on a medication, and it is working perfectly with no side effects nor interactions, then great! on the other hand, this is a class of medications to fully inform yourself about and to make adjustments as necessary. Watch out for weight gain, especially!