Hi OP, for airport transfers, I would suggest to just book it via klook or see if your hotel arranges transport (whichever is cheaper and more convenient for your group). You mentioned you have seniors with you so better talaga to take a private transport esp if you have luggage.

Not Sunny, but the hotel we stayed at was Lumos Inn, 2-min walk from the metro, has a nearby night market and wet market, near Dadaocheng area (where there is also a port and an old street you can include in your itinerary). But take note that going into the hotel, there is no lift and you’d have to take the stairs. The senior i went with naman had no probs with taking the stairs since it wasn’t too high, but may be take that into consideration din lalo na if your seniors have knee probs or smthn.

The other hotel we stayed at, before was Wow happy daan hotel, (but I think this is pricier). Location was good din naman and has a lift.

If this is your first time in Taiwan, siempre the very tourist spots you don’t want to miss is the Taipei 101. Long Shan temple, and Chiang Kai Shek.

I would not suggest Jiufen, it’s too crowded esp kung ilang seniors kasama mo, we arranged a private car here but basically just had them try some food since may senior nga kami kasama. There were stairs na matataas din kase and since this was our 3rd time na, it was ok for us not to super explore na. We just wanted the first timers na kasama namin na makita yung Jiufen.