As you have seen in the key generation page you can generate an address for all coins in the pool using your private key, so you can start mining just using a Vertcoin miner, for example sgminer:
http://sgminerwindows.com/ sgminer --nscrypt -o stratum+tcp://poollo.com:6666 -u yourpublickey p x
To check that payouts are being made you can download the h2o and giarcoin wallets and incorporate your private key or check on blockexplorers with the public key you can see on key.html page.
I have never imported a private key before, but I found a guide, and I get this:
./BellaCoind importprivkey "(the private key I copied from your keygen page)"
error: {"code":-5,"message":"Invalid private key"}