> How much do you pay into those if you're not earning anything?

Afaik (and I really don't know for sure, because luckily I had never the misfortune to need it) it is paid by the welfare system. However, there are many rules and obligations to be edible and honestly, I wouldn't want to have to deal with the bureaucracy. There are several steps towards this. First, after becoming unemployed, you'll receive unemployment support, but only if you've worked before! They also demand that you use your own savings and securities to support yourself. After that runs out, you'll receive the bare minimum monthly allowance, which is around 300 to 400 Euros per month. You don't get that easily. As long as there are relatives, the state is very likely to get the money from them first. You'll also get free housing, but that's also far from what one desires (bad neighborhood, very small, etc.).

> Do you still get health benefits when unemployed?

Very likely, because health insurance is mandatory for everyone. So the system is built upon the idea that those who are able to pay also support those who are unable. However, it is very frowned upon to "abuse" this system and rest in the social hammock (that's a very literal translation, sorry). That's because the whole social system is regarded as a safety net, but not for individuals who don't want or can't contribute.