RBS 1.6: Real Bid Success Bug Fixes Required!

I have installed the script RBS 1.6 aka Real Bid Success reverse bidding system. It is open source software that is comparable to a scriptlance clone. I have modified the original programming to correct the HTML bug's but I am illiterate when it comes to php. I require a professional that can resolve all the bugs/fixes listed below. The list of bugs is long but the majority are simply tasks that should take no more than 10 minutes. Simple bugs: • Categories require underscore if space is require • Guest contact form does not send user email or subject • Disallow cross account duplicate usernames, a freelancer and webmaster cannot have same username (error otherwise) • Add transaction issue in admin panel, does now allow you to choose username • Ability to add an ‘other’ checkbox button to post a project page where user can fill in a form to say what other categories are required (up to three other options) • Allow multiple file uploads to job post’s • Place space between job type,no space,between,commas(example) • Discard draft button not working • Remove hour requirement from bid page • Bid posting php error message "Trying to get property of non-object" • Allow negative balance only when freelancers accepts a project • Remove everyone option from escrow payment transfer • Move canceled projects to closed projects section in view my projects Moderate Bugs/Fixes: • Paypal payment gateway function (supposed to work) I am just unsure where to point the paypal handler and what the required URL is for -make sure payment system is working correctly • Support ticket to become threaded forum type discussion with their comments first and admin response under theirs with an option for them to reopen ticket by replying • Similarly edit project message board to have a similar threaded forum style, and clean up few issues -can only see message details relative to you -when selecting post message to everyone that is only supposed to be submitted to freelance bidders, not all freelancers -check for other issues • My project notifications in admin to display when review for user was posted, when project has ended, when freelancer has been chosen for project