i have just put in a built motor here is its specs

callies stroker crank
eagle rods
je 8.5:1 pistons
cometic mls head gasket
arp headstuds
using a treadstone turbo kit with a hahn portfueler

(all of this was donewith the 5psi spring in the waste gate)
Now here are my issues it started first crank and i had a small fuel leak where i pluged the hole where the stock fpr used to be, so i shut it down fixed that. Then carfully watched for other leaks there were none at the time, so i take a cruise around the block then check again. still no leaks so a take for a little bit longer drive about 8 miles in which never took it over 2500rpms then i got back and relized at some point my oil pan gasket started leaking. i had lost about 2 quarts of oil at this point i kind of freak out.turns out there was a loose bolt in the oil pan i tightened it up and it stopped leaking replaced the lost oil, but the i restarted the car and heard a little rattle that went away after 30 seconds of idleing then when it went away i reved the motor a little to probably about 3000 rpms and the rattle came back and went to a clunking quickly i shut the car off and now i am here.
the oil pump was a replacement stock one i believe

the questions
is it my oil pump?
is it posible to replace it with the motor in the car?
should i ask the motor shop to replace it on account of the leaky gasket or shoud i just suck it up cause its my fault?