Translation:I see the children and they are all happy.
Non Hebrew speakers who want a run down of this: "חוץ ממנו ששונא את כולם"- Not grammatically correct Saying what I said translates to "except for that one who hates everyone", just maybe in a slight slang-ish way of saying it. "חוץ ממי ששונא את כולם"- That's a more general way of putting it, as in "except for the one who hates everyone" In this case, the way I worded it is the correct way in this situation, specifically since I was referring to a sentence in this lesson that stated "I hate everyone-אני שונא את כולם" (Native Hebrew speaker going through the course for fun)
There is no default gender. Both of them are used regularly. It just depends on what sentence randomly comes your way. Bear in mind thsf masculine is also used for neutral speech, so in general it is used more, especially in the plural. Don't worry, you'll encounter more feminine verb forms as you go down the tree.
Also, there are just two voice actors - one male and one female.