I ordered f4 v3 pro from bangood, but it looks like it is not the pro version because some reviews say that it’s not pro. Are there any connection differences that’ll fry my FC?
The main difference is that the pro has a compass sensor on it.
The earlier versions had a few more differences but comparing the regular f4 v5 to the pro f4 v3 that is the main difference. We mainly still sell the f4 pro v3 for use with iNav. If you are flying betaflight I would suggest you rather consider the omnibus pro corner or omnibus fireworks as they are newer and better designs than the f4 pro v3
Hope that helps 
Project Blue Falcon has a really informative video on them all. Really worth watching them .