Hi W.,
I hear a lot of frustration in your post. I think, if you are finished with the preschool, that's fine, and as preschool teacher/owner myself, I wanted to give you a little insight to take to your son's next preschool. Some of this is informed by my work privately and some are observations from my years at larger preschools/daycares.
First, while parent/teacher communication is important, there have to be some understandings. One understanding I have with parents-- and I even have this in my handbook-- is that I will never discuss the children in front of the children. At pickup, my communication with parents is very cursory at best, just those quick "busy day today... she was happy because we had the big easel out"-- this sort of thing. I will send home a note if something important has happened, and if the child is hurt, an accident report will be sent home to be signed and returned. (This is both for parent information as well as my insurance records.) Overall, though, my families know that if they have anything other than a brief 'how was their day' question, they should give me a call later on.
You don't mention why you contacted the director regarding your son being scratched, however, this is something that's usually addressed to the teacher first. Directors are extremely busy, so unless there's an ongoing problem which is not being resolved, I always suggest discussing it with the teacher first, and then a note in writing to the director, asking for fifteen minutes or so of their time or a phone conference. (Please know, I am not excusing the person you are upset with, but just sharing my experience.)
My preschool currently is a small group of children, however, when I had a group of 8 toddlers, there was no way I could attend to my group and have concentrated conversations with parents. Next to drop-offs in the morning, pickup time is a huge transition for our groups. My primary job as a teacher is to be tending to the children who are present and need my help and support. From my experience, having a parent try to discuss something in-depth when I have a room full of tired kids who want to go home is a lose/lose situation for everyone. It's one of the most demanding times of day, and I would often ask parents politely "I'd be happy to discuss this later. Give me a call" or "It sounds like we should schedule a half-hour for a phone conference".
Also understand, too, that from the perspective of child educators, it's bad form to discuss the children in front of the children. We know that kids are listening, and sometimes these discussions have the potential to hurt the child's self esteem or to cause them anxiety. I've been approached by well-meaning parents with some topics that were not appropriate (from my professional point of view) to be discussed in the presence of the child or their classmates, who also absorb this sort of information and make their own judgments about the child in question. This is to respect ALL of the children in my care. And I can't discuss any another child's challenges with you, either, so if Bobby hits Suzy, all I can tell Suzy's family is that she was hit, what sort of first aid, comfort, and follow-through I provided. I can't tell them that it was Bobby, or what Suzy and Bobby's relationship dynamic with each other is, nor what sort of communication/plan is being made to help Bobby stop hitting. All I can tell Suzy's family is what is pertinent to their little girl in particular. As a teacher who is held professionally to confidentiality in these matters, I have limits on what I can share with each family and have to use my own good judgment in assuring that all the families are equally respected.
Me, personally, I never have parents email me. When we are in the midst of problem-solving, lots of emotions can arise and I need to see a parent's face or hear their tone of voice, and they need the same from me. Even parents whom I know outside of school are asked not to use email for school-related communication, but to call. The same goes with the preschool which my son attends. I've known the teachers and director for years socially, but all my communication regarding my son is either done in person or over the phone. This way, we get the best communication possible in real time.
I hope this provides a balanced picture of parent/teacher/director communications in this setting. One book you might consider delving into is called "The Essential Conversation" by Sarah Lawrence-Lightfoot. This discusses parent/teacher conferences for older children, and may shed some light on the subject for future insight.
Best wishes for your future preschool situations.
H.