3. Social Media
Not as main site
Getting back to social media again, be sure that you do not make a Facebook page your main site. A friend's church did this and made it look like they couldn't afford the electric bills even as they were raising money to build a new church. Really, it's akin to your minister showing up in a rusty, oil-burning 1988 Chevy pick-up with Back Off! mud flaps. If that is the case, then a Facebook page would be fine for you.
Drive to site
Be sure your social media is set up to direct viewers to your website, whether it's Youtube, Facebook, or whatever else you might use. They usually give you the option of adding your own webpage as a link, so do that. Then, embed in your site and promote those cute videos and photos with members. You need a back and forth relationship, but never post an important article that people would want to read on the social media sites. You must post links to articles ON YOUR WEBSITE. Let people like or make comments if you want social interaction badly, but be warned that articles with 0s for shares and likes look a bit lonely.
Hosted for you but not integrated
It's great that someone wants to host the bandwidth for you, but they want their users to stay on their sites. You need to be vigilant about integrating social media posts into you own webpage. A CMS with a useful plugin can usually help.
The dangers of social media include personal pages that are part of work pages or inappropriate communication between individuals. Your organization cannot fully control what happens on these sites, so you might have some incentive to avoid them. However, a pastor without a Facebook page looks like he's either Amish or living two centuries ago, so it's probably worth the risk.