The whole dangerous thing probably something you should have looked into before you started doing it... but no, it's not dangerous. I wanted to do this and asked my gyno about it, and she said it's not bad but not to do it for any more than 3 months/cycles.
The difference between Seasonale/Seasonique and taking regular pills consecutively is that on Seasonale for two months, the last week of what would be placebo pills are blue... so in the entire 3 pack, you only have one row of placebos (12 weeks per cycle). If you take 3 packs of BC continuously, you ignore the last week that you would have had "period free" and begin a new pack (9 weeks per cycle). This means you get your period more times a year than you would if you were taking Seasonale. If your insurance covers it and if you really don't want to get your period as often, I would consider switching to Seasonale since that is what it's designed for and you will have less periods. Personally, I don't love having my period but I feel more at peace knowing I'm not pregnant every 9 weeks rather than every 12 weeks so I'm okay with taking 3 consecutive packs of regular bc. Plus, my periods have been lighter since I began taking my bc like this, so a few more periods a year are not a big deal at all. But I can easily see how it would vary from person to person!
HTH :)