Are there religions were ALL immediate family members take part in the wedding ceremony?
I only know of Judaism doing this:
1. BOTH parents escort the groom
2. BOTH parents escort the bride
3. ALL brothers and sisters take part in the wedding party
4. Grandparents - even great-grandparents - can either stand onstage or sit onstage in chairs
Ancient Indian weddings indeed involved members of the clergy. The ancient religions of the Indian subcontinent include Jews, Hindus, Muslims, Sikhs, Jains, Buddhists, and Christians, among others. All of these religions have used clergy to officiate wedding ceremonies, both in the past and present.
Yes! A Wiccan wedding ceremony is called a hand fasting. It is beautiful. They can be used by people who are members of Pagan (polytheistic nature religions), or by people who don't necessarily share the same beliefs. There are also Christian and other folks who chose to use handfasting as their wedding rituals for various reasons, so don't feel excluded form these resources.