Hi
Your "same problem" stance, makes me think about this story.
One guy complained of headache after drinking Gin and Coca-Cola.
Same problem after Whisky and Coca-Cola.
Same problem after Vodka and Coca-Cola.
He, very logically, decided to stop Coca-Cola.
To comment seriously, I would say that Word, though it's probably the best "classical" text processing application, is probably not the best tool if your final aim is to produce EPUBs.