Does tendering one's resignation after performing Salāt al-Istikhārah mean that the job is evil, or does an involuntary event have to occur to know that?

The reality of Istikhara is entrusting the matter to Allah so that He may choose what is best, and its sign is success in the matter or lack thereof. Chest tightness and crying may not be an indication that there is no good in the deed, and its cause may be ordinary. Consulting experts is a good thing, and they may be a reason to deter you from the deed. Obedience to one's father is obligatory in matters that benefit him and do not harm the child. If you fear harm from the deed, then obedience to your father is not obligatory upon you.