Magento 1.9: Layout Theme & URL Rewrite

Hi,

Basically I've got a new job editing a Magento store website for a client. I have zero experience working with magento and it's starting to stress me out!

First problem I've encountered;

Basically overnight my site was 404'ing and Web Server Rewrites seemed to be the culprit. Disabling it removed all the 404 errors and my site could function, but it broke some of my images and returns 404 to them (even though they are definitely there with correct permissions).

Shown here; http://i.imgur.com/SiNggv6.png

I've even tried editing the .htaccess file to disable the Rewriterule with;

rewrite everything else to index.php

!--RewriteRule .* index.php [L]

I'm a bit lost now as I didn't change anything to the site and it was working perfectly and now this... any ideas?

Second Problem;

I'm trying to add a Left sidebar navigation but everytime I install an addon to do this it always ends up the top of the page and not the left (as in, under the menu but ABOVE the slideshow I have there). I've tried looking for a layout.xml and cannot find it in my directory anywhere. Very odd.

Thanks, Stephen

P.S. website is; www.pc-tek.com.au