Is it permissible to do something whose permissibility or impermissibility is doubtful before seeking a fatwa, and is Istikhara permissible in this case?

A Muslim must know Allah's ruling on an action before undertaking it. He should not deem permissible what he is ignorant of its ruling or what he doubts. Actions differ: The default rule for acts of worship is to stop until there is evidence [for them], while for customs, permissibility is the rule until prohibition is established. For intimate relations and properties, prohibition is the rule until permissibility is established. Istikhara (seeking guidance from Allah) does not determine rulings; rather, it is for hesitation regarding a permissible action. As for rulings, they are known by asking people of knowledge, in accordance with the Almighty's saying: "So ask the people of the message if you do not know." If a fatwa is unclear to someone, he should seek clarification from the people of knowledge.