I am of the opinion that there is a difference of interpretation and an actual heresy. To my mind, a heresy either denies Jesus or denies a teaching / lesson of Jesus. The end time prophesies often fall into the category of interpretation and do not align well with the label of heresy.
Jesus taught that no man will know the hour and day of his return. Under that teaching, I believe that it is far more prudent to look to ones own salvation and not worry about the end times. Simply because our own end time can happen at any moment. Car accident, heart attack, stray bullet, what ever reason, can end ones life unexpectedly.
Live as if you have to answer for your sins and rely on the promises of Jesus each and every day.
I agree we should look to our salvation first and foremost--but not solely.
As Christians, we need to be prepared for what comes our way. It's a lot like that story about the guy stuck on the roof of his house during a flood. We need to prepare to care for ourselves, our family, and those believers who may/will need us when the time comes.
We've been told to turn our plows into swords, and Ecclesiates tells us there is a time and place for everything. I'm not saying we should hasten confrontations, or be combative. But we sure should be ready for whatever may come. Be like the prepared virgins waiting for the Groom.