Is developing a friendship with a priest a bad idea? No would be the short answer and yes my long answer.I often perceive a priest who wants to be my friend as not truly living out his vocation.
Priests focus should be completely on God and seeing the laity as his spiritual children not his friends. That’s not to say we cannot get close to priests and come to know them but a line must be drawn.
The priest needs protection from worldly relationships and likewise those of us laity need to avoid dragging the priest into our own worldly life and interfering in his relationship with God.
They say absence makes the heart grow fonder but with a priest ( I suppose you could apply this to us also ) absence makes the heart grow darker and colder.
The priest needs to keep himself closer to God as he needs to be a light for the rest of us who are more prone to become a victim of darkness. If the priest lives in darkness and we live in darkness, how can he guide us to the Lord? It would be like the blind leading the blind.
I always err on the side of caution when a priest wishes to become my buddie. Not because I think he’s evil but because I fear he may gradually lose his light that he’s obtained through prayer and closeness with Christ.
I’d much rather a priest become my spiritual father as this is a much more healthy encounter with your priest but that’s it.