T-V Distinction in Romanian

I haven't been able to find any documentation here regarding T-V distinction when translating from English to Romanian. Which forms should be used? For example, should “You could do this” be translated to „Ați putea să faceți asta” (second person, plural — formal, polite, often used when addressing strangers), or to „Ai putea să faci asta” (second person, singular — informal, often used when addressing acquaintances, or strangers evidently younger than/as old as the speaker)?

If there is no convention set yet, I'd lean toward using the second, informal, and more direct way of addressing the reader for simplicity and “friendliness”.

As a side note, should one use English or Romanian when writing messages here? I've chosen English in this conversation for accessibility, assuming there won't be many native speakers reading this discussion page in the near future.