I got what i wanted! It is indeed accessible to two exits M3 with escalator for luggages and M7 without escalator. The hop on hop off meeting place was just at the taipei main station which is like less than a 5 min walk. Ms Hannah is kind who allowed us to stay until 3pm because our flight is 8pm. It gave us time in the morning to visit the Presidential palace. She responds immediately to my messages. If i were to return in another season i will use her unit again.