The warnings come from IC2 being a coremod and are bogus/unsubstantiated. I'll just delete all package infos/@API support since Forge refuses to fix its bugs and it's commonly misused.
I am thankfull that you took your broken usage of the IC2 API but it seems that you didnt understand how to use the package.info API.
Let me explain you what it is for.
The PackageInfo API (API API in short) is there to Split the API in 2 ways,
1: First that people are no longer forced to use all parts of an API and do not cause issues
2: Second and most important is that you can split the API from the mod so that mods can still use the interfaces and benefit from the things they provide.
Simply a Indirect OreDictionary.
Simply COFH API is based around that concept. COFH is not required but everyone can still use RF without having to check for specific mods. They search just for the API and thats it.
Its a very basic but well running & userfriendly system. The idea behind that is very good.
Also it seems that you have missunderstood the concept and did not even use it properly and call it bad on their side...
I told you how to use it right and you still say its used wrong on common bases?
No its the same thing as the getDisplayName issue i had to tell you to fix it, or the getUnlocalizedName that you had to change twice to make it work properly how it should has to be done (when you just could it done with one time fix)
It seems like more that you do not understand common based systems because FMLs PackageAPI system works as intendet & the idea is behind to split the API with these package API infos into components so you can ask for stuff with @Optional and do not require a mod for that is very good and people did think themseves something when they created something like that...
Edit: And FML Is throwing Errors because you used a Splitting system to mark all components as the same. Which is equal to not using it or using only 1 packageinfo. So you used it wrong.