Oily scalp doesn't cause hair loss, it's DHT that cause the hair follicles to degrade and cause hair to become thinner to the stage that they fall off easily. However, the sebaceous gland attached to it remains the same size and it continues to pump out about the same amount of oil. So as ur hair thins, u will notice that ur hair becomes flatter and oilier. This and itchy scalp is the early symptoms of MPB.
For ur case, since u r still at a early stage, i wouldn't recommend fin, period. I suggest u use Nizoral shampoo 2-3 times a week as it is effective in ridding dandruff and itchiness. Keeping a clean scalp is the first step in maintaining ur hair, esp like u and me with oily scalp. Monitor ur hair status, if it worsen, u might have to add on other treatment. But most importantly, stay healthy n dun over-stressed on ur hair.
Take care.