Leonardo, you've done SO MUCH for Plone so obviously you're free to do anything you want. Just remember that in the long term if what you start isn't sustainable, it might be better not to start it. The other thing to consider is: if you get tired or are unwilling to continue doing it, who will take over doing it?
Yes we use HootSuite for Plone, PloneConf, on Twitter, Facebook. Used to be able to connect it to LinkedIn groups but LinkedIn has cut that off this month. Also, the LinkedIn group really is dead and for a long time now has consisted of only our HootSuite-pushed announcements. Last month @sneridagh and I started Instagram accounts for PloneConf and Plone, which in THEORY can be connected to HootSuite but I haven't been able to figure it out so far.