On the first question, definitely not the second alternative. The word “Desculpe” is usually used like “excuse me” and not really “sorry”. But “pedimos desculpa” is also a bit too verbose, like “we did something wrong we shouldn’t have” 
. The best would be:
“Lamentamos, mas ocorreu um erro ao exportar os resultados da sondagem”
On the other one, the first one that begins with “Precisa” is the best one. The other can actually fit portuguese from Portugal and it isn’t wrong or inadequate in any way, but is just a tiny bit less adequate. 
On “Staff”… that’s not an easy one. The usual translation is actually “Pessoal” (never “Personal”), that’s the word we use in portuguese culture and society, but it can feel a bit awkward in the Internet forum context. “Pessoal” usually refers to employees running a business in the real world. That’s why many times we tend to use “Equipa” (team), “Equipa de Moderação” (Moderation Team) and similar when relating to virtual stuff and not “Pessoal”, since the word also means “Personal” (as in personal message) and can be confusing once you have it as a title/link somewhere.
On that dropdown key, I’ll have to check the context to understand what it means before I can say more.