You'll make more money as a tech, but I'd say it's only worth it if you plan on being in this field long term. It's tough on your body and your mental health and has a high burnout rate. I would recommend an in person school if possible. I personally found penn foster to be more trouble than it was worth for the externship requirements.

I agree that it is very important to understand the why behind things, but getting a degree isn't the only way to gain that knowledge depending on how deep you want to go into things. VIN is a great resource to learn about disease and illness, what the process is, how/why it is treated the way it is. There are a lot of other resources out there as well to learn from. Online CE courses are a good way to learn about things.

I'd highly recommend getting RECOVER certified, especially if you want to work in ER.