"He likes beer too much and drinks as often as possible."
Translation:Li tro ŝatas bieron kaj drinkas kiel eble plej ofte.
It's perfectly fine to 'trinki' alcohol, it just depends on the circumstance.
For the most part 'drinki' indicates intention not necessarily excessiveness, ie drinking alcohol with the intention to get drunk.
Meanwhile, you would not use 'drinki' for someone simply having a sip of an alcoholic beverage to taste it, ie a wine taster, or a curious teenager at a family function and also drinking the wine during communion at church. Here 'trinki' would be better.
"kiel eble plej..." is sort of a fixed expression thing (sorry, don't know the technical term). So you say things like "kiel eble plej rapide", "kiel eble plej multe", "kiel eble plej longe" and "kiel eble plej ofte". If the 'eble' follows the 'plej' I don't think it makes sense.
It's an idiomatic construction and follows a particular pattern, so variants are probably wrong. (I say 'probably' because I don't claim to be an expert). The lesson for this is buried under "Animals 2" on the tree:
That page, interestingly, has information that would weigh either way. As much as it talks about "kiel eble plej ofte", it also refers to "Tiel... Kiel" as a correct construction for "As (blank) as (blank)"...
This is very curious. When I first learned Esperanto 30-40 years ago, I think the textbook specifically taught the "Tiel... Kiel" variant. (I think I still have it somewhere... will have to look.).
Thank you for the referral back to the tips and notes, nonetheless. A good review for me.