Buddypress & Wordpress theme compatibility

I’ve install buddypress on my wordpress website, and I do have another theme installed as well, and made them compatiable. But the buddypress structure is broken now, and I will need to fix the followings: 1. The registration form: Need to customize it to fit my website theme. 2. The sign up form: Need to be customize so as to fit my website theme. 3. The Buddypress account area: Need to be customize in order to fit within my website theme. 4. The log in, and registration link: Need to eliminate the buddypress top bar, and link the log in and registration form on one of the menu as shown in the image below. When users are log in, the menu should show logout, not registration, and when logout, show both login and registration. I’ve also include an image showing how I want the user area to look like when log in. Thanks.