yes. there are ticketing booths just outside the zoo

Yes, the Giant Panda House is closed during every first Monday of the month. Just a reminder too, get a panda-visiting ticket at the zoo entrance before you actually head to the place. It is free, it simply indicates the visiting time so the crowd inside the building can be manageable.

Yes.

Open year round every day (except for Chinese New Year's eve, 4 February 2019). - from their website

Not sure, but you can always check on their website which is very updated

We actually visited on a Tuesday and all animal exhibits were opened. Taipei zoo’s indoor exhibits are closed on Monday by turns so please check their schedule before visiting. The penguin house is closed every second Monday of the month as per their published schedule.

TWD$65 per head No extra charge for Pandas

I really haven't a clue. You should contact the zoo!

If you don't want to take the gondola, you may go straight to the ticketing booth of the Taipei Zoo. And ride a train going to the top station and walk from their. Hope this helps.