Procrastination can definitely be deadly. It seems to me to fall out of the fact that Fi and Ti are all about optimizing and critically evaluating in the moment. It's good for telling one that now isn't a good time. It's not so good for telling one when a good time will be, or even breaking things down into more manageable steps.
The flip side, from my perspective, is that a perceiver fully in the flow is hard to beat. So it's all about making the most of when the time is right, and figuring out how to limp along and line things up so the time will be right later.
And there are tricks I play on myself (I think I've posted this somewhere before) such as setting a ridiculously easy goal for myself to force myself to become interested when starting a project. Those first few starts are about as pleasant as pulling teeth, but once I'm sufficiently into something momentum is much less of an issue. Also having a deadline (and I hate deadlines) is helpful for reigning in the perfectionism. It shifts from "must be perfect" to "must be as good as it can in the time left."
Also, minor things (like bills) are best when dealt with instantly. Guilt is a great de-motivator, so not letting things build up enough to induce it is good.
I admit I haven't been so good with creative endeavors on my own, though. There are no external deadlines, no one is waiting impatiently for the output and perfectionism can kill the enjoyment pretty quickly.