loststar67,
Block Buster and Road Opener are actually pretty different. They can work together but I wouldn't combine them in one spell. I would recommend using Blockbuster first to blast through obstacles and then Road Opener to make a clear and easy path to you and your goal.
You don't have to use an oil with the herb mix. After crushing it up very fine, you sprinkle it in some freshly melted wax and then roll the candle in it. Once the candle has fully burned you could use the oil to dress your feet in the morning so that you are led directly to your goal.
This page gives some great details on how to roll the candle in the herbs:
http://www.luckymojo.com/blockbuster.html
Wishing you the best of luck!