I can understand that geniş zaman should be used for benze but I have heard benziyor been used when they meant it in the wide tense. Is the incorrect use part of turkish slang or maybe the person had forgotten their grammar from being abroad for so long?  ---> It is not wrong to use "benziyor" , In my opinion, people use both ways.

e.g. O Kim Kardashiana benziyor.   ---> This is right too. If you mean "someone who looks like Kim Kardashians in appearance  " It is more like "outlook wise] [at the moment], when we see someone who is looking like "Kim Kardashian" we can say "  O, Kim Kardashian´a benziyor. Because we just saw her outlook.

or

O, Kim Kardashiana benzer.---> Using aorist in this case is more like as you said below " she always looks like Kim Kardashian[naturally, resemblence could be in her behaviours or her personality]

Can both be used when you mean she always looks like Kim Kardashian (naturally) not she is looking like Kim Kardashian at this moment (through clothes or makeup).

I hope I´m making sense because I am a bit confused lol