Let us clarify what your friend has said.
Firstly, no one here will tell you what to do; that is up to you to decide.
Regarding alcohol, Samael Aun Weor was very clear in his writings. Read the chapter linked below.
"With the sinister demon Algol, it is impossible to make compromises, arrangements, or any kind of crooked deal. Alcohol is very treacherous and sooner or later will stab us in the back. Many people with Thelema (will) only drink one or two glasses a day; a terrific ruse, isn’t it?" - The Mystery of the Golden Blossom
As stated in the teachings and known by science, alcohol is a poison.
"There is no question that being a product of disintegration... alcohol has a vibratory disintegrating, dissolving and destructive tendency, drying our tissues and destroying the nerve cells, which are then gradually substituted by cartilage.
"It is clearly evident that alcohol tends to eliminate the capacity for independent thought and calm judgment since it fatally stimulates fantasy. It also shockingly debilitates ethical sense and individual liberty."
In other words, alcohol promotes the exact opposite of the path.
You said, "This path is not a path of deprivation." Actually, this path is 100% about depriving the EGO of what strengthens it, such as fornication, drugs, alcohol, etc. The consciousness, the BEING, does not need or want alcohol.
There are many foolish people who, desiring to prove they are not "fanatics," drink alcohol. Perhaps they prove they are not fanatics, but they also prove they are stupid. This is how their ego fools them easily. Wanting to prove themselves strong, they instead prove they are weak.
Nevertheless, there is evil in good and good in evil. This is how we sometimes find medicine in poison. There are medicinal treatments that utilize small amounts of alcohol. These treatments are not sufficient to create intoxication. If someone becomes intoxicated, they have consumed too much.
The line you quoted about being able to handle a drink does not mean that one should willing drink alcohol (especially just to "prove" something). Rather, it means that one should know how to handle social situations with grace: holding a drink does not mean one gets drunk. In this case, the graceful one avoids offending his hosts, yet also avoids intoxication. This is how we fool the foolish.