Customizing a running Wordpress theme

I already have a functioning Wordpress theme and I need some customization both at frontend and backend. The things I need: - Basic frontend login functionality, registering in frontend, not through Wordpress (I can buy any plugin - Codecanyon or something like that - you may need). The user has to have the ability to look into his profile, see his name, his points (which will be added through backend by the admin) and the poker games he is registered for, which leads us to the second part of the customization. - The theme already has a custom post type that is fairly close to what I am looking to achieve and it's showing at the homepage through a widget. I need to strip away all the unneccessary details and only have the following to that post type -> title of the poker game and the date of the poker game. That's all you fill in in the backend. In the frontend, the user is able to see all the details and is able to click a button "register", which adds the title of that poker game to his profile in the list of the registered games and also to the backend for the admin to see. We're talking about pure PHP and HTML, all the styling and stuff you can leave up to me. I just need the functionality part done. Let me know if you are able to make these customization happen, I can provide you with further description and the site address so you can check it out. Thanks!