"difficulty" : 0.00003052,
"hashespermin" : 18,
Looks like initial diff is too high.
diff=0.00003052 => 131082 hashes / block.
If we've got 50 machines mining at 18 hashes per minute, the total network hashrate is 15 h/s
=> mining a block takes around 2.5 hours
That's about accurate. The difficulty was set high, and the rewards were set very low. This is nothing unexpected. Once blocks start getting mined, the difficulty adjust will take place. This was to ensure that blocks don't fly off the shelves.