No matter where you go there are going to be "bad" people. Luckily, there are laws on the books that let people know where the sexual offenders live. I went to http://www.meganslaw.com and put in your zip code--there are 7 sexual offenders in your area as well.
If you truly want to move down here to be near your in laws, the best thing is to come down here and visit, and find the area of PSL that you like. Then, visit the website, and see if there are any sexual offenders listed near the area that you like.
If I can help you in your search for a home, I would be happy to help. Feel free to email me (firstname.lastname@example.org) or call me (772-486-4306) and I can provide you with any additional information that you would like.
Have a wonderful day
Debbie Redditt, CRS, ePRO
Prudential Florida Realty
Your in laws are right--this is a beautiful area!