If Link's body regresses back to a child-like state, when he returns to the past, then how do you explain his clothing? He would've had over-grown clothes on. Also when adult Link is in the red or blue tunic...you time travel and are wearing a green outfit as a kid. Don't tell me any BS about him hurrying up to change clothes, before we see him! Then again with your explanations--you'd try to run with that idea. We see Link the instant he's transported back, taking his hands off the MS.
Ok, then, smart guy. How does Link get into an appropriately sized outfit the first time he goes into the future? Did Rauru come by with his tapes and pins and tailor up a new tunic, some pants, and then think "You know, he might just want his ears pierced" and then did that too? NO! That's utterly ridiculous. It's just one of those discrepencies we are all glad to ignore because if it didn't happen that way we'd see Link penis.