[SOLVED] Starting over... clean slate... same blog...

I am wondering if there is any way to do this without way too much trouble.'

Like many noobs that started blogging without a clue as to what they were doing, I have over time installed and uninstalled hundreds of plugins, edited code, changed css and possibly broke every rule to properly building a fast, responsive blog.

As with everything in life, experience is a great teacher. Too bad that gaining much of that experience comes from trial and error.

I like my site just the way it is but it has become bloated with broken code from old deleted plugins, useless tables and options in the database and other crap. So my question is this.

Is there a way to install a fresh new version of Wordpress, install just the plugins I want and keep the css just the way it is while maintaining all connect-ability to my 5000 plus posts and images.

Basically, I want a fresh start without losing everything, and I want to keep everything just the way it is without having to rebuild it all from scratch.

Is this possible? Is there any way to clean and fix everything without doing this? A code or site checker that finds and identifies problems, plugin conflicts, etc?

I guess my ideal fix would be to build child site with fresh new WP, newest version of ATA using the same theme CSS as I have now. Then adding one plugin at a time, optimizing compatibility of that plugin before adding another to easily recognize conflicts as they occur... while keeping my current site up and running until the transition is complete. Then installing the new site without breaking any connections with the DB...

A long but important question... any ideas or documentation pertaining to this would be appreciated.