2. How to debug HTML site?

Use http://validator.w3.org/ to validate your HTML website

3. Explain Debugging of Joomla Extension?

I use a problematic Joomla extension called Hot Property (RC1) that causes more than 300 simultaneous mysql conections, and also high CPU consumption (although the site has minimum traffic).

4. Explain PS3 Debug/TEST/Prototype Console?

Good luck finding a PS3 debug or test because like the Wii dev related stuff there hard to find at the moment. For the PS2 Tool try ebay but expect to pay and arm and a leg.