I am going to say yes, is it safe NO, a transfer pump is cheaper, and designed to handle diesel, some hyd. pump seal can be destroyed by diesel fuel also. The only hyd. pump I would use if you had to...
yes a motor can be used in place of a pump on most applications. the difference between a pump and motor is the intake and discharge port sizes. on a motor they are the same i.d. on a pump they are...