can someone tell me about this debug messages and warnings?

[sickenlysweete]

vmdebug My selected language by getParams(com_languages) en-GB
vmdebug self::$_jpConfig->lang en_gb
vmdebug vmTime: loadConfig db no: 0.00403308868408
vmdebug Start used Ram 9M
vmdebug vmTime: VirtueMartControllerUpdatesmigration Finished task updatesmigration: 0.509629964828
vmdebug End used Ram 10.5M
vmdebug Peak memory peak 10.5M

Extension Manager: Warnings:
The PHP temporary directory is the directory that PHP uses to store an uploaded file before Joomla! can access this file. Whilst the directory not being set isn't always a problem, if you are having issues with manifest files not being detected or uploaded files not being detected, setting this in your php.ini file might fix the issue.

The value of the upload_max_filesize in the php.ini file is greater than the post_max_size variable. The post_max_size variable will take precedence here and block requests larger than it. This is generally a server misconfiguration when trying to increase upload sizes. Please increase the upload_max_filesize to at least match the post_max_size variable or vice versa

[jenkinhill]

The VMdebug info is OK.

The Ext manager warnings come from Joomla itself and relate to server php.ini settings that may affect Joomla extension uploading & installing. See http://jaswanttak.wordpress.com/2012/05/01/joomla-extension-manager-warning-php-temporary-directory-is-not-set/ and  http://www.ostraining.com/support-forum/joomla-support/extension-manager-warnings/