>Using notepad++ (or whatever other program) in a manner that deals with internet content a lot - then updating is the thing.

Disagree. It's hard to screw up a text editor so much that you have buffer overflows 10 years after it's released, so it's probably safe. It's not impossible, but based on a quick search (though incomplete because google is filled with articles describing this incident) it doesn't look like there were any vulnerabilities that could be exploited by arbitrary input files. The most was some dubious vulnerability around being able to plant plugins.