"... which would help get faster, therefore farther ... "

Faster does not necessarily mean you'll be able to go farther. There's nothing wrong with doing intervals and trying to get faster, but if you want to do a century, you're going to have to be able to sit in that saddle for 6-10 hours depending on how fast you do the century.

1 hour intervals will not prepare you for how that saddle will feel at the 4 hour mark ... or how your digestive system will react to food and your sports drink of choice ... or how your shoulders and neck will feel. You've got to start increasing your distance, and when you discover aches and pains you can fix them by adjusting the bicycle or changing the saddle. And along the way you can experiment with food and beverages to find something that will work for you. You'll also be able to build up your "mental endurance".

Bicycle fit and nutrition are much more important than speed (especially short distance speed) for completing a century.

And yes, you can keep the aerobars ... just remember not to use them in a crowd.