Since you've already bought it, I wouldn't let all this scare you too much. I hear story after story, some from credible sources, about
and their pH problems. Before I converted to completely organic, I used both with excellent results. BTW, I have been on other grow sites that had a generally very high opinion of Fox Farm mixes.
Happy Frog already has myco's and humic acid, so you won't need to add any.
Don't put any lime in your mix unless you study first so that you aren't just wasting your time. For one thing, it takes two-three weeks for lime to adjust the pH and if you don't know how much you should add... well, that's just not a smart thing to do.
All that said, there are some mix suggestions in the organic forum you might want to check out before you get another bag. Also, as a new grower, you may be able to benefit greatly by using the method Muddy and Jackal are teaching people, with great results... Muddy and Jackal are good friends to have when you're just getting started growing... it is their passion.