Configuring fuel gauge IC (BQ35100) with USB-I2C converter
Yes, you certainly can configure the fuel gauge IC with your own I2C interface and, when the IC is embedded into a system, you will do it from your own code.

But the IC is conveniently supported by a system configuration applet called Battery Management Studio, BQSTUDIO, with all registers properly displayed and broken into individual control bits, with designations in accord with specification. Unfortunately this applet only understands the TI interface adapters like Ev2400. While it is pricey for DIY, but it will speed up your development. 

The BQ35100 is a complex chip with elaborated control over several sophisticated algorithms, and uses SHA-1 hash encryption for some parts, see Programming Manual. The EV2400 and bqSTUDIO  will help you to wade through all these intricacies, which will guide you with design of your own code. I would highly recommend getting the EV2400 box.