Are EAs and HFT bots allowed?

Yes. You can trade using HFT bots, EAs, and automated strategies.
Please keep in mind that HFT bots are allowed only during the Evaluation stage and are prohibited on a Funded account. 

Also, it's important to be mindful of the challenge rules when selecting strategies and EAs. We do not allow abusive trading such as arbitrage, hedging across multiple accounts, or other forms of cheating. Don't use these strategies to avoid account suspension.