The CRC numbers are very dependant on if the line is fastpath, interleaved or with G.INP active. It also matters which ISP you use, as different ISP's allow different amounts of errors.
0.09/per min is just under 6 per hour and around 130 per 24 hours. That's perfectly acceptable and absolutely of no concern. We don't watch the CRC figure so much but rather the ES (Error Seconds). An Errored Second is a second containing one or more CRC errors (or various other errors). 130 CRC's could mean 130 ES, but it could also mean 1 ES (If all 130 CRC's happened in the same second).
Your ISP's ES threshold is likely to be either 1440 or 2880 per day. You likely have under 100 ES per 24 hour going by your 0.09 CRC's per min figure. I have no idea why AVM have raised issue with those CRC rates as they look low to me. I would guess from those numbers your line is fastpath, though that's just a guess. If it is then those numbers are not just fine but excellent.
I'm unable to help with the PPPoE errors as this is an area I'm less familiar with. You would need to expand on what you mean by error though. Is the Fritz!box simply dropping the PPP session?
