But then when Duolingo gives us a multiple choice with "They", we are made to select both the "Ellos" and "Ellas", even though without context, it should only be "Ellos". I understand what you are saying, but they are being inconsistent.
When they ask to give all correct answers, I am assuming they mean all grammatically correct answers that would translate to what they have stated. Este was a grammatically correct translation, so it seems it should be an accepted answer.
I see no problem using "Este". What if I point to a car and say "Este me gusta màs."? The context is known. DuoLingo should consider all possibilities when grading otherwise we`ll all go out pointing and saying "Esto" for what should be "Este" or "Esta".
To me the reflexive form seems to be the appropriate one. I think that if the subject were a person then the reflexive form would definitely be needed... perhaps it's different with inanimate objects? Are there any native speakers around to help?