If you only run one Tinder account with ASB Tinder Bot, you do not need to buy a private proxy. You will need to buy a private proxy when using two or more Tinder accounts. ASB does not work with public proxies.
ASB Tinder Bot runs on an emulated platform similar to the Tinder apps used for Android. Therefore, your Tinder account(s) will be completely safe. The accounts can only be locked if you do not abide by the rules on Tinder.