PHPProbid - Fix Issues and Create New Feature

I have purchased and installed phpprobid. There are a number of small bugs/issues to work through and then a new feature is required before it can go live. It would be helpful if you have experience of phpprobid but it's not essential. There is a demo on their website which should help you to understand some of the requirements below. Note that I will provide more detail on each of the elements below before going ahead with the project. If possible, I would like to be able to apply PHPProbid updates, without affecting any of the changes below. BUGS / ISSUES 1) Re-position cart button on main menu. 2) On 5 different forms: Hide the Country field & default to UK. Hide the State/County field and make it optional instead of required. 3) In 4 different sections: Stop Country and State/County fields from displaying. 4) Hide 4 sections on the search filter: Price, Show Only, Format, Location. 5) Allow a non-registered user to view all pages except the listing detail page. Will require either a pop-up message or an error message on the page with links to login or register. 6) Ensure username and password cannot be the same when creating a new account. 7) Admin and users are getting 2 copies of all emails. 8) Five copies of the newsletter email are being sent. Could be related to above issue. 9) Emails from admin are going into various junk folders. Not sure if anyone can help but possibly worth routing mail through a service such as Sendgrid? 10) When Admin approves a new buyer/seller account, the approval email is not triggering. 11) Possibly help with PayPal integration prior to going live. NEW FEATURE - ALERTS Whenever a user searches or browses the system, there should be a 'Create Alert' button. This will pop-up a box allowing a logged in user to enter a Title for the alert and also choose the frequency i.e. Immediate, Daily or Weekly. They should then receive an email whenever NEW items are added matching their criteria. Also in the Members Area, add a new Alerts section where the user can View, Edit and Delete their alerts.