144 hr China Transit Visa

I am US passport holder, want to travel to mainland China using the 144 hr transit visa. Can I have the following itineraries: (1) US-Kunming-Hongkong for 6 days. Stay in Hongkong for 5 days (2) Hongkong-Xian-Taiwan for 6 days.

While stay in mainland China, can I still use all google apps, free WIFi or I should get the eSim card locally?