So is the word 'meg' similar to 'pedig'? I wrote 'The musician is waiting inside, but the singer is walking outside'. Is meg more used for 'and' and not 'but'?

These are actually two sentences in English. In my answer I wrote: The musician waits inside, while the singer is walking outside. The use of the word "while" is equivalent to "whereas" to indicate a connection and help make it into one English sentence. Is walking and walks are both the same here. It is not necessarily an ongoing action but rather a comparative one.

Is there a way to discern whether simple present or progressive present should be translated, or should I report an error as it could be either?

Is this female singer a primadonna, or maybe even a diva? She's wandering around outside while the musician (perhaps her accompanist) is waiting inside. Did they have a disagreement? Hopefully they'll eventually get their act together!

I put female singer but it is being rejected. No other way to put the sex in english so I will just leave it.