6 hours later and debug mode still hasn't been turned off, even though you told him exactly how to, in his own thread. Unbelievable. Most of the web devs I know would have panicked, fixed the setting and redeployed within minutes of learning they'd screwed up in a visible and embarrassing way.
Inspire confidence this does not.
Yes, its a matter of changing the debug value to 0 instead of 1 in /app/config/core.php. If this were set you'd be getting 404's instead of error messages.
@OP - This probably isn't the best place to sell your site, but you're going to need a lot more stats if you want to sell it anywhere. At the very least you need to show proof of revenue over time. A good place to start your asking price is 8 * monthly_profit.