Well, just to clarify: If you don't want to be a meteorologist, you shouldn't get the degree, because that would make you a meteorologist. I don't think any school's going to have a two-year program in meteorology or something like that...either you get the certificate or you go to school like I did and get the four-year program.
If you're interested in online courses, I know that Penn State does offer an online meteorology course (Meteo 101) that might be of interest to you. The problem is that in order to really get involved with meteorology, you need the math skills, and thus, I think most schools would rather teach it in the classroom, because it is one of the most rigorous science majors not in the medical field.
I would say this: If you don't want to be a meteorologist, get the certificate from Penn State. Otherwise, you're going to plunk down thousands of dollars for a hobby which might not be of interest to you in a few years.
As for storm chasing, be forewarned (from someone who knows a lot of the Vortex2 team personally): 98% of it is driving under sunny skies and eating bad food at truck stops. The other 2% is under a storm cloud, praying it will pop up a tornado. It's BORING and is NOT like what you see in Hollywood or TV. You'd be disappointed, trust me.
(A lot of people think you get three tornadoes every day and six EF5's over one summer. *buzzer*)