They get nervous when that have to go and when they are hungry. Answering your question yes.
Yes.
Very easily. What happened?
Syrian hamsters are solitary, and absolutely don't care if they're alone.
Not necessarily. It depends on how well your hamster is cared for.
easily agitated
yes but they can catch cold and die easily
Jumpy. Easily frightened or nervous.
They can carry mites. Easily treated with powder from the pet store.
They can get pregnant just like any mammals that are in their fertile cycle. Typically after 8 weeks after being born is when a hamster can be impregnated but some can get pregnant even sooner.
probably not that easily. You should buy them Chinchilla dust. It's a sand bath and they wash themselves and never wash them with water because they get cold easily.
A nervous temperament can be of a nervous person who is constantly anxious or represent a sub-group of temperament of the ancient Greek Medicine, such as the melancholic, sanguine and choleric.
It depends on what music you play. Hamsters are calm and peaceful when they listen to classical music (they may even sleep because they are so relaxed). But, if they listen to rock music they may get a bit jumpy and can get nervous. You could experiment with lots of different types of music, but hamsters probably prefer listening to classical music.