Clean / Optimized / Secure Coding & Optimize MySQL Database Server Load

I need a php/mysql expert in these areas. Serious bidders will PM their past work that they've done that is relevant to what I'm asking for. All else will be ignored. Also accept other bid offers. The script is around 40kb * - Clean up my script and keep the codes manageable. I modded a few things and the coding is getting disorganized and messy. - Optimizing queries, tables and php for processing/load time and size. - Add more security to avoid sql injections. - Making sure it is error/bug free.