Can I use Beacon of Hope to buff allies that weren't injured?

Beacon of Hope
Source Inner Sea Gods pg. 207 (Amazon)
Your hope inspires allies in their struggles.

Prerequisites: Channel energy 3d6, worshiper of Milani.

Benefit: When you channel positive energy to heal living creatures, those you heal gain a +2 morale bonus on saving throws, attack rolls, ability checks, and skill checks for a number of rounds equal to your Charisma bonus (minimum 1 round).

Would allies (and enemies that I didn't exclude with Selective Channel) that weren't injured but that were hit by my channel gain the buffs?

Strictly speaking, probably not since it says "those you heal".

But I wouldn't run it that way.

I haven't had a GM say it doesn't work. I will be coupling it with Spirit Boost at 7th level. I don't think it is optimal, but I like the gist of it.

I would say no as the RAW, says those you heal.
Now I could be wrong as it could mean those you target with the spell/effect get X, Y, Z, etc.

And you could always house rule it how you liked.
MDC

Would allies (and enemies that I didn't exclude with Selective Channel) that weren't injured but that were hit by my channel gain the buffs?

Creatures healed by channeled energy cannot exceed their maximum hit point total—all excess healing is lost.

Channel Energy still heals targets, so I say yes.

I haven't had a GM say it doesn't work. I will be coupling it with Spirit Boost at 7th level. I don't think it is optimal, but I like the gist of it.

I'm fairly sure you can't combine those on the same effect since spirit boost says it triggers when your healing spells help someone.

Yeah, I retrained Spirit Boost once I realized it didn't apply to channels.