I know that ALPHA conferences were originally Anglican but many parishes are using it. Has it been revamped for Catholics or does it water down Catholicism to work with other faiths?
I am not personally familiar with the program. However, it does appear to have a Catholic version. The USCCB newsletter as well as a few other Catholic leaders seem to have a good opinion of it:
Alpha for Catholics (www.alphausa.org) provides ten basic sessions to introduce the faith to people who do not attend church and to inactive Catholics who are loosely connected. The meeting environment is designed to be friendly and nonthreatening so that participants can explore the faith in a manner that relates to the questions they have. The leaders of alpha have discovered that the sessions also reinvigorate active Catholics. A simple meal helps to gather people together. In addition to the ten sessions, the program includes a one- or two-day retreat conducted away from the parish. The Alpha Essential Kit consists of an array of resources (books, videos, and posters) for inviting people to join, conducting the sessions, and training facilitators.
Alpha’s website: What Catholic Leaders Are Saying