No Touch ID after Motherboard Replacement

So i bought a realllly cheap iphone online...Its iCloud locked.. Bad ESN... So figured if I purchase a used or new motherboard online to install wouldn’t that basically clear the phone of a bad Esn and have a fresh iCloud ? there is a catch to replacing the mther baord according to the site i am getting it on…. . IT BASICALY SAYS THAT THE TOUCH ID WONT WORK AND THAT I HAVE TO USE ASSISTED TOUCH TO OPERATE THE PHONE.. IM GONNA COPY AND PASTE WHAT IT SAYS ON WEBSITE OF WHAT HAPPENS WHEN I REPLACE MB

The battery efficiency is less than 90%. It is easy to have automatic restart/automatic shutdown/calorie.

2.7/7P/8/8P/8X needs to match the vibration. If there is no vibration fingerprint, there is no touch. The non-quality problem is the vibration mismatch.

3.7P/8P needs to match the screen. If there is no match, there will be no touch or no touch.

4. When installing, please installed motherboard and other accessories firstly , then install the battery, otherwise it will easily lead to burning the motherboard or the screen.

5. When installing X motherboard, do not touch the dot matrix refractor (face recognition) after power-on, otherwise it will not be able to recognize face.

Pls pay attention : due to the motherboard without Touch ID function,so,u can't use the fingerprint identification and home button function after installed,the home button without reaction when u pressed it,u only could use Assistive button to operate,pls note this,thanks ! 

WHAT DOES ALLL THIS REALLY MEAN IN ENGLISH.. IS IT HARDER THEN IT SEEMS TO BE ABLE TO BUY A ICLOUD LOCKED PHONE, REPLACE MOTHERBOARD AND MAKE IT NEW AGAIN? OR IS THAT NOT POSSIBLE BEACUSE ALL THE PARTS IN BETWEEN ARE LINKED TO THE MOTHERBOARD EHICH MAKE THE PHONE UNSUABLE