This is not legal or tax advice. Talk to a lawyer from your jurisdiction

Your question is how can we own property with minimal risk:

Particularly in the USA, there is a great deal of liability involved with ownership of rental property.

One needs to consider inside out and outside in asset protection.

Inside out - being liabilities arising from within the legal entity that could
Outside in - liabilities arising personally, whereby the legal entity is "up for grabs" in court

I would have each person own thier share in the apartment legal entity with another legal entity.

Owner Alfred has an LLC holding co
Owner Brad has an LLC holding Co
Owner Charles has an LLC holding Co
Owner Dick has a trust

Alfred Holding LLC: 25% of Apartment complex Corp
Brad Holding LLC: 25% of Apartment complex Corp
Charles Holding LLC: 25% of Apartment complex Corp
Dick Holding Trust: 25% of Apartment complex Corp

This way you get both outside in and inside out asset protection, and each person can transfer thier assets without having any difficulty. Also can pass on to heirs much easier, and gives added flexibility for each owner. It also provides a "double layer" of asset protection because of the holding company for each individual.

As a bonus, you could register your LLC in a state that doesn't require names to be registered on state docket, so your name won't appear in a simple asset search from an overzealous creditor.

To read more, check out these websites:

www.Flagtheory.com
www.AssetProtectionWorldwide.com