I would say, people uploading files to your forum should be fine. First, if you are relying on the InfintyFree storage and not a CDN, make sure users can’t upload files greater than 10 MB (because of the file limits)
Second, limit what files can be uploaded to avoid malware and other bad things. If any are detected, it will suspend your account.
Third, make sure that your forum doesn’t include any copyrighted content. If it does, and the scanners haven’t picked up on it yet, make sure to take care of that.
Lastly, make sure your forum has good security. You are using bbPress, which is within Wordpress, so security is going to be good. Make sure nobody breaks in though.