Sorry, friend, but you're kinda stuck.

No matter what else happens, you WILL absolutely be required to show up at least one day to check in and attend orientation. You will likely be on call for one to two weeks, and if called during that time, may have to show up for a second day to sit around in the jury pool. Usually, if you're not selected for a trial on that one day, this completes your obligation (at least it does in the two jurisdictions in Maryland where I have been called for jury duty in my life; other jurisdictions may do it differently).

Prior to your orientation day, you can ask for a postponement and you will generally be given a choice of preferred weeks. This is in case you have commitments that are absolutely unavoidable; I rescheduled once because of a non-refundable trip. But since you are given three to six months of advance notice, you are expected to be able to re-schedule your other commitments to allow service, either on the primary date or on a postponed date.

In other words, you absolutely can not get out of jury duty in advance. You will definitely be called to serve at least one full day, perhaps two, even if you don't get selected for a trial.

Now, as to voir dire, I find that the fact that I have relatives who are police officers, including my own father, generally makes me completely unsuitable for any sort of criminal trial. If you have any relatives or close friends who are in law enforcement, or have been in the past, this will probably make you undesirable to the defense in a criminal case. For civil cases (i.e. lawsuits), you just have to bite the bullet and hope you don't get selected, or that you have some other factor that would bias you and make you undesirable to one side or the other. I highly recommend that you do not lie during voir dire; you are essentially committing perjury and can be charged with a crime if the court suspects that you're lying to get out of your commitment. Be respectful, be honest, and do the best you can to fulfill the obligation and make the best of a difficult situation.

I realize what a difficult situation this puts people in, but the best you can do is take the advance notice and use it to your advantage. Re-schedule as many work commitments as possible away from the week of your obligation. Don't schedule new ones, or personal ones, during that week. If there are any that absolutely, positively cannot be missed, apply to re-schedule your jury duty service. But you'd be surprised at how understanding clients and potential clients can be when you tell them flat-out that you have jury duty that week and ask if you can schedule earlier or later.