These are pretty serious accusations that you are talking about here. And for serious issues as such, we must be serious both in engaging the qualified authorities to investigate before pronouncing judgment, as well as in scrupulously avoiding wrongful accusations and gossip. Satan of course is always after our leaders. Some leaders unfortunately did falter and have brought great scandals to many. Satan can equally create confusion among us. And woe to us if we become divided and wrongfully bring down our pastors, who are standing in Jesus’ place for our sake, or a place of worship, which is where God dwells.
A distinction needs to be made here as well. You mentioned “attacks”. Satan is always attacking each one of us, as well as our homes and churches. So if it is merely attacks, that’s normal. The real concern is when we are not fighting and standing firm in God, employing whatever necessary spiritual tools we have available to renounce his works.
So, if you have serious reasons to suspect that a priest or leader is already compromised, or a place of worship is compromised, depending on the situation, you should first fact check with the priest responsible for the place. If that is not feasible, or the situation is not improved, you should contact the diocesan office and report it. Meanwhile, you should withhold judgment and submit it to the rightful authorities. If nature is truly diabolical, I believe the only proper persons to make that judgment is the responsible bishop, the chancellor and the diocesan exorcist. It is certainly not a regular lay person or priest.
I don’t know about other dioceses, but I was trained that if I suspect something diabolical is manifesting, I am to report to the diocese to investigate.
Lastly, a word regarding the validity and efficacy of sacraments celebrated by a priest. The Church has long ago declared that the validity and efficacy of the sacraments are independent of the sanctity of the priest celebrant. Every priest of course is a sinner. If the efficacy of a sacrament depends on his sanctity, then we would be hopelessly deprived. A sacrament is valid whenever a validly ordained priest celebrates it with the correct ritual. The efficacy of the sacrament is always full, though whether or not we can receive it fully depends on our faith and openness to God. It is with the eye of faith that we can look beyond the poverty of a sinful priest, to receive the merciful God mediating through a sinner with great efficacy.
Obviously, a priest’s lack of sanctity is a great scandal and stumbling block for the faithful and the world, especially for those who are weak in faith. It dismays those who desire to enter, causes the weak to stumble, and even at times wears off the strong. We must therefore pray for priests every day. We must also not abandon the sacraments because of weak and sinful priests. Let us not allow sin to spread, but counteract it with acts of faith. It is amazing to hear the stories from priests who have been brought back from the blink, because of the few faithful in their flock who refused to abandon the sacraments and kept praying for their conversion.