For starters 1.5 inches of shingle overhang is way too much. Imagine a shingle hanging out that far. It would curl and droop all over the place. 0.5 inches is acceptable. Second, you should always have a drip edge. Installation may require that you carefully remove (and replace) roofing nails from the starter strip of shingles. You should not push the drip edge tight against the fascia. Leave a few mm or if possible have it overhang the gutter.

For starters, 1.5 inches of shingle overhang is way too much. Imagine a shingle hanging out that far. Look around at well-built homes. You won't see that amount of overhang. The shingles would curl and droop over time and the edges would crack and crumble. Up to 0.5 inches is acceptable. I wonder if the commenter is confusing drip edge overhang and shingle overhang. The remaining advice from the person suggesting this is equally suspect, regardless of whether they did this professionally. You should always have a drip edge. Installation may require that you carefully remove (and replace) roofing nails from the starter strip of shingles. You should not push the drip edge tight against the fascia. Leave a few mm or if possible have it overhang the gutter.