can we change our iphone passcode by apple id

No you can't, your Apple ID is different from your Passcode but if you format the phone you can use your Apple ID to sign in without the passcode

No

Apple Inc says; "We read all feedback carefully, but we are unable to respond to each submission individually."

Here is how for iPhone · Country or region* Select your country or region. · Feedback Type* Select feedback type. · Comments* Enter a comment.

Feedback - iPhone - Apple