Yes you need Ariesve ops file.
I don't think you can flash stock firmware via feacore recovery
but you can flash feacore recovery with adb if you have a rooted phone.
Dude forget all you learnt in the htc forum
samsungs are different to flash new recovery youll have to do it via odin ,Feacore recovery menu or adb
it's feamod* mate , feacore is the kernel