unable to install any update

Hi, i've just purchased our capulus template & installed it.
First of all, Joomla seems unable to write configuration.php. I put it in 777 manually using FTP to make change in system configuration.
Furthermore it's impossible to update any component (i.e. language of site administrator) in any method (package, url, folder)
:::::::::::::::::: Error message :::::::::::::::::
Warning
Warning: Failed to move file!
Error
Archive does not exist
Unable to find install package

In the homepage section the feature section is not displaied, error message:
Warning: imagejpeg() [function.imagejpeg]: Unable to open '/home/laborse/public_html/site//images/resized/media/k2/categories/1_692_456.jpg' for writing: Permission denied in /home/laborse/public_html/site/modules/mod_noo_accordion_slider/helper.php on line 598

Thanx for any suggestion you could give me.

Dear Marco Besana
Thanks you for using product our.
Please give me link your site and your account of administrator via private message.
I will check it for you