Contact Form issues

Hi, I am actually trying to accomplish three things, all of which are related to the Contact Form:

1. Allow public suffixes that are longer than 4 letters

It looks like I need to modify the regular expression in onetone_contact(). I just don’t know how to override this function in a child theme.

2. Restore the info a user typed in the form after a submission fails, e.g due to a typo in the email address

I can not use inline php. I am thinking my alternative would be to use a javascript. I have very little experience doing this kind of programming and I am hoping someone would offer some professional tips here.

3. Clean up the messages such as “Message sent successfully”, “email invalid”, etc. I would like for them to go away upon a new submission, rather than staying on the page.

This one is beyond me. I have not clue how those messages magically appear under the form 🙁

Thanks beforehand!