Second of all, who would put him/herself self in such danger for ~950€ a year (actually less since the operator of this service obviously wants his share)? If the user did something illegal with the card, the nominee could get into serious trouble and I don't see how anyone would willingly sign up for this. Another possibility could be that these persons actually don't exist. Come on, use your brain.
There's nothing to worry about. I've been using the service for 5+ months already and I never had money unauthorizedly drained from my account (just one occurrence of my card being blocked that was my own fault, after buying some service that had a screwed-up payment processor - which AlexPCS handled flawlessly by the way).
It's just very very hard to imagine someone would be willing to act as a nominee for that kind of money. Doesn't matter what the rules of the service are, if someone ignores them and uses the cards for lets say terrorism or something like that, the nominee would be screwed. Even for 10x the money I can't imagine anyone signing up for this because they could literally have special forces kick in their door the next day.
And about the reviews.. It's just that lots of these accounts have multiple posts but have been inactive for years and post the same review "At first I was sceptical but..". Nothing personal and maybe it's just a coincidence but my bullshit meter is just going crazy.