Performance troubles with Motorola Moto X Force (Android 7.0)
Imho a phone with a 4x 2.00GHz Cortex-A57 + 4x 1.50GHz Cortex-A53 (Qualcomm MSM8994 Snapdragon 810, 64bit) and 3 GiB RAM should not have such problems.


No, it should have such problems. SD810 is known to have bad thermal performance (it is essentially a SD410 when under load because all a57 cores shut down). The only thing you can do is do factory reset and remove all junk from your device or install a custom ROM (or a custom Kernel) which has thermal profile that suites your usage pattern. 

(I use a Oneplus 2 with same SD810 btw)