In theory it's pretty safe. In practice it depends on how much of the network you think has been compromised by various governments. If you are downloading some music or a movie or some adult material your fine, the government in general could care less. If you are looking for something truly illegal (CASM etc) then you deserve to be caught anyway, so go ahead.

Extremely. It’s just slow, but once you get used to that, it’s solid.

Depends on your definition of safe. But it's way better than a VPN in every way. The only problem is that there are less people seeding over I2P

As far as I know, yes. If I were doing something a little more criminal, I would be somewhat hesitant, but it is still better than a vpn for privacy / piracy / private piracy. The speed does suck tho…

I've used I2Pd for a few months without vpn and haven't received a letter yet so I guess it's working. I don't notice any change in speed but I only get like 30Mb/s anyway