1) Yes, I visit alphaphialpha.net regularly. I also maintain
www.notablealphas.com which (humblebrag) is a little more timely when it comes to "good news" of chapters. It also serves as a master list (in progress) of notable members of the fraternity.
2) Yes. I actually follow all the NPHC orgs and do a regular unofficial evaluation of how I think they are performing. I don't think Alpha has an instagram.
3) I would like to see more NPHC orgs on Pinterest. Alpha is on Pinterest but I can tell it's not a priority for them.
4) The Sphinx Magazine is in print and PDF. The mailed copies are notoriously late. I prefer the print edition but the stories are not timely. I would say the bros prefer to share chapter news on social media and would like to see more feature articles in The Sphinx.
5) I haven't been to a convention or conference since 2009. Sorry I can't be of more assistance on that one.