If I transfer property to a friend or relative to keep it out of bankruptcy, how long do I have to wait so it is safe from seizure?

Possibly up to ten (10) years, at least if you also owe an unsecured debt to the I.R.S.

Court cases are holding that a bankruptcy trustee can "step into the shoes" of the I.R.S. in such a case, and use the 10 year I.R.S. statute of limitation to extend the normal state statute of limitation that would otherwise apply (4 years in Texas, for example). In re Kipnis, US Bankruptcy Court, SD Fla 2016.