Thanks for the feedback guys! ^
No endorsements for betel nuts then!

The only reason for the Holiday Inn is the Pointbreaks deal, equivalent of USD30/night... (had booked the Éclat initially)

I have emailed a couple of car service companies asking about transportation from the airport and the possibility of stopping by the Longshan temple and surrounding night markets on the way to the hotel. Then we can do Yongkang Street the next day... I guess that should be doable? Also, I suppose as first time visitors it doesn't make a huge difference whether we substitute Shilin for those night markets?

Will do the NPM first thing in the morning on Saturday, aim to arrive in good time for the 10AM English guided tour. I assume a taxi would be the preferred option from the hotel? There is also a free shuttle to the Taipei 101 area, where we can catch the metro but that will probably be more hassle and take longer...