Yes. When you sign up you won't be asked for payment information at all.
I made F5Bot so I could use it myself. After a couple months of usage, I decided to share. It doesn't cost much to put it up for everyone to benefit.
Yes. F5Bot scans both submissions and comments. See here for more info.
No. Keywords and phrases will match regardless of capitalization.
Yes. You can enter a partial URL as a keyword to track. Make sure the "track whole word only" box is unchecked.
You can post your keyword or phrase on Reddit in the test subreddit. You should expect an email from F5Bot a couple minutes after you do.
Each account is allowed a maximum of 200 keywords. If you need more than that, please contact me. Don't create multiple accounts to subvert the limit.
Additionally, if a keyword is hit more than 50 times in a 24 hour period, it will be disabled. You can manually re-add the keyword from your account. Keep in mind that F5Bot is designed to alert you about fairly uncommon keywords or phrases. If you're trying to monitor a very popular brand, this might not be the right tool for you.
Maybe. Let me know if you have any ideas.