I would like to setup a Raspberry Pi as an onion router, but I have some questions about it.
At home I am using a Fritz!Box to connect to the outer world (to the net of my ISP). Would it make any sense to put the RasPi behind such an router when it runs as onion router.
(I would like to still be able to access this obscure outer world outside the Tor network with other devices - depending on the sense and security at the same time or at different times but without time consuming reconfigurations.)
How should I setup certain firewalls (in general and for this certain case)? (Firewalls on terminal devices as well as on the routers)
@Edit: I am not sure if it is a good idea to change the question - the question shows that I have a certain lack of expertise in the topic. I saw/googled other questions concerning TOR that had negative votes but showed that I am not the only one with certain problems to understand the context. I think it is important to keep this questions for people who are new to the topic as I am. (For example I wasn't sure in which way a TOR Router and a relay node correlate and also about the exact rules I am able to apply - can an relay node which I use as entry node prohibit other users to exit the TOR network. Would it be suspicious when I am the only user accessing and exiting the network over this node? I mean I know how Mixes/Mix-Networks work but I have several knowledge gaps concerning TOR and as I am not in a community where I can ask people in person I will sometimes ask imprecise questions.
I basically ask these questions to fill my knowledge gaps and to understand which risks are there and how to prevent them. Just knowing about the algebra and certain security/authorization/authentication/encryption/signing/anonymization-protocols and even formal methods to find vulnerabilities in protocols doesn't really help in practice.