Eccentric billionaire Stephen Cloobeck’s friends tried to warn him to break off the relationship with his fiancée long before he was arrested on suspicion of witness tampering and threats involving her criminal case, the California Post has learned. “A lot of the people who were involved in his life tried to help and he didn’t want the help, and they’ve chosen to walk away because it’s too toxic,” a source with knowledge of the situation told The Post. The source branded Lavie a “master manipulator.” Adva Lavie has been charged in an alleged scheme to target rich old men for burglary via dating apps. Lavie has used multiple aliases, including Shoshana and Mia Ventura, according to law enforcement.…