Agreed mostly. Put other stuff -- mostly water, but some food -- in your stomach, and be aware of the volume and ABV of your one drink, and you can be fine.
Source: I occasionally drink, but it's rare enough that doctors' offices tell me to answer "No" to that question.
That's not true. As long as you compensate with a bit of water, and you drink quality spirits rather than shit, one or two drinks are absolutely fine even for the low-volume drinker.
Source: am one.
What makes a real difference is that, if you're super-fit and super-lean, your body will struggle harder to deal with alcohol, so you will have to over-compensate by drinking a lot of extra water (and hence piss more).