Hello Arin,
If is possible to use the Google Translate API without using any other services of Google Cloud Platform. However, the Translate API service itself is part of Google Cloud Platform so "being on the platform" is required. Simply
complete the setup to enable the Translate API after creating the project and you won't necessarily need to be using other services of the platform.
I believe you're referring to the
Translate API Quota Increase Request form. If you need to translate a fixed amount of 3 Billions characters, you can do so with the default quota over a few days as it can be
increased by yourself to up to 50 Million characters/day. If you need to translate higher than 50 Million characters/day, you can fill out the quota increase request form along with your project-id.
I hope that helps. Cheers!