The church should have churches and not just on the Internet. By only using the Internet they are not reaching everyone that they could be and are also not laying roots to stay around instead of just being a fad. By building churches they are giving their congregation a place to meet and talk face to face and to become more established.
This is their church, and they can run it however they want to. If they decide that they want to break away from the traditional church methods, that by all means do so. If they like how it is run, and people follow it, then that is all that matters.
No, the Universal Life Church should remain an online-only institution. Providing its services totally through the Internet makes these programs accessible to the widest array of viewers possible. It also saves the organization money. Interest in online business and increasing public presence are pushing many companies online, so the Universal Life Church enjoys the best return on investment by refraining from creating brick-and-mortar locations.
The Universal Life Church has always done things non-traditionally with very lose doctrines. Their main belief is essentially just "be good". It seems to fit their character to be non traditional and online only. A big reason that they exist is to ordain ministers in non traditional religions or no religion at all, and I don't feel that this necessitates having brick and mortar meetings.
The Universal Life Church should not have brick-and-mortar churches rather than an Internet presence. The majority of churches are brick-and-mortar, so this allows the Unniversal LIfe Church to differentiate itself in the type of institution it is. It also allows for special ordinations so people can more easily get married.