There are many reasons they don't do both of your requests.
They don't have the email alert loud, because many iPhone users are business users. And most either have multiple email accounts on their phone, or receive 100s of emails a day. Having a loud tone go off everytime an email is pushed or fetched, would be very annoying. And that goes the same with an email repeat alert.
Having said that though, it wouldn't hurt for them to give us the options to choose it. Seems Apple doesn't give us enough options for many things.
I heard that in the earlier OS's when you clicked 'close' on a text, it would just close the window, and keep the 'unread' text badge. This is the way I'd prefer it, until they create a "quick text" mode that allows you to text back in an app, without closing what you were doing. They decided to get rid of that, and make it appear read if you click close. I wish they would give us the option, not just assume this is how everyone wants it.
"Show message as read when closed is tapped - ON/OFF"
Something like that.
Actually, better yet, they should have a little "x" in the top right corner of the message. Click close to act like you've read it, hit the little "x" to ignore for now and view it later.