I am a liberal Christian and I appreciate at our school how all religions are celebrated. It can get a bit confusing at times, because what is emphasized changes from grade to grade. I have heard our Kindergarten described as Paga with its Harvest Festival, Winter Spiral and Spring parade where the children are greeted by Lady Spring. In second grade, the children learn Saints and hero stories so it can sound very Catholic with all the talk about St. Martin, St. Elizabeth, etc. In third grade, the children are immersed in Judism and the study of the Old Testement stories. There are Jewish holidays and shabat every Friday. Fourth grade it is the rowdy Norse gods and goddesses as well as Native American spiritual stories. I have been told that in 6th grade they will study Islam.
I view the school as not religious but one that recognizes the spiritual in all of us. There are the outer trappings of many of the Christian holidays but what really seems to be celebrated is more the cultural and folk aspects of the holidays. They also celebrate Japanese and Hispanic holidays through their Japanese and Spanish classes. At our school, we have Christian, Pagan, Jewish, Buddhist, Atheist, etc. families who seem to be comfortable witht the recognition of the inner spirit or soul.
It has never felt like a cult or particulaly occult to me. Peolpe come and go from the school for various reasons and remain the community's friends and often return for festivals. I have friends who are Wiccan and witnessed many occult activities which I have never seen in the school.
That being said. Every school is different. The Kindergarten can be worlds apart from the grades. Your best bet is to talk to parents and get involved in some manner if you can. Observe, talk and ask questions. Take it a year at a time. Major decisions about continuing can be made along the way. We have re-evaluated every year by looking at the pluses and minuses at re-enrollment time. I have 2 children in Waldorf - one in 2nd and one in 4th. We have been in Waldorf since Kindergarten.