sounds like you did your hw.
for a crankshaft stopper you can either have someone hold the crankpulley with a breaker bar/socket while you pull the flywheel off or just jam a big flat head on the edge of the block and flywheel to keep it from spinning.
Spring pins can be reused as long as you didnt bend them, washers on the trans drainbolts can be reused, just clean the surfaces well and torque to spec.
I found a hand siphon pump to be awkward but, i'm sure it would be fine if you have a lift and another hand. when i refilled my rear diff i dumped my landlady's handsoap pump and filled it with diff fluid...worked perfect