Keyboard, SSD, one of two RAM sticks, WiFi card, and honestly basically everything else except one RAM and the CPU/GPU look replaceable on the T14 and P14s, with a publicly available manual to guide you: https://download.lenovo.com/pccbbs/mobiles_pdf/t14_gen1_p14s...
Comes with 2x USB-C, 2x USB-A, HDMI, Ethernet, 3.5mm headset jack, MicroSD.
That said, the Lenovo online shop is a customer service disaster. Don't buy there. Misadvertised the smart card reader as a SD/MMC/... card reader, defrauds customers by advertising a "best price" policy that they then refuse to honor, 3 months to shipping with repeated delays, they play stupid games with their pricing (e.g. they jack up the price during week days by about 30% to milk business customers), zero flexibility (e.g. if the shipment is delayed because they're missing the removable RAM, they can't change the order to ship you a unit without the RAM, your only option would be to cancel and go to the end of the queue).
Also, poor hardware support for the GPU and possibly Bluetooth under Ubuntu 20.04 LTS.
Comes with 2x USB-C, 2x USB-A, HDMI, Ethernet, 3.5mm headset jack, MicroSD.
That said, the Lenovo online shop is a customer service disaster. Don't buy there. Misadvertised the smart card reader as a SD/MMC/... card reader, defrauds customers by advertising a "best price" policy that they then refuse to honor, 3 months to shipping with repeated delays, they play stupid games with their pricing (e.g. they jack up the price during week days by about 30% to milk business customers), zero flexibility (e.g. if the shipment is delayed because they're missing the removable RAM, they can't change the order to ship you a unit without the RAM, your only option would be to cancel and go to the end of the queue).
Also, poor hardware support for the GPU and possibly Bluetooth under Ubuntu 20.04 LTS.