Does Furious Focus remove the attack penalty incurred from a Reckless Rage, which may or may not be similar/the same as Power Attack?
Furious Focus does not remove the penalties from Reckless Rage
Benefit: When you use Power Attack while raging or while using raging song, you take an additional –1 penalty on melee attack rolls and combat maneuver checks, and you gain an additional +2 bonus on melee damage rolls. Modify this damage bonus appropriately based on the type of weapon you are using, as normal for Power Attack.
While Furious Focus only requires you to use Power Attack and wield weapons two-handed to apply it's effects. But it only removes the penalties from Power Attack and no other feats:
Benefit: When you are wielding a two-handed weapon or a one-handed weapon with two hands, and using the Power Attack feat, you do not suffer Power Attack’s penalty on melee attack rolls on the first attack you make each turn. You still suffer the penalty on any additional attacks, including attacks of opportunity.
You can see clearly that Furious Focus affects Power Attack's penalty, and if Reckless Rage was supposed to also affect this penalty, it would (or should) use a similar wording. But you can never know for sure, since they were most likely written by different authors.
If I can advise you, do not take that feat, its inferior to many options to increase your damage and it costs a full feat for the effect of a fraction of Power Attack. Basically, all this feat does is to count your character level as 4 higher to define the effects of Power Attack.
Considering this, it isn't unthinkable to allow Furious Focus to also apply its effects to Reckless Rage, in order to improve the feat a little bit. It will only affect the very first attack each round and it will cost the character three feats.