As for the buying the new MBA. I'm actually going to wait a bit. I bet the new models will be out soon anyway. As of right now, things are actually decent. This way, I can manage to have (what I call) a "cushion" to be able to add a few more "bells and whistles".
I was advised the last time I was on the phone with Apple to install two apps called Monit and Malwarebytes. I have noticed that the fans are so quiet, I can't even hear them again, when this all started, they were always going. I think I have mentioned before what apps I was advised to remove, and one of them was a temperature app (SMC fan control)
Though, if it gets really bad again, how old is too old to get parts for? I am using a mid-2012 right now and when I thought I was going to need new parts, I read somewhere that my MBP was "too old". So, I'm keeping my eye on things and if it gets really bad I am back to square one.