Wordpress Errors

Yesterday my website (that has been live and working fine since the begining of this year) went down and I was getting an HTTP Error 500.0 - Internal Server Error (see attached). I contacted my host and they informed me that there are no web records, and they did something to fix this. The site went live, but had error messages all over the live site and I couldn't log in the WP-Admin. The host told me that the problem was: Some plugins within your WordPress site relating to syntax and variables not properly set. Please pass this info onto your developers to investigate further. I have left Debugging on during this process. Notice: Undefined index: aiosp_enabled in \\BNE3NAS2-CONTENT1\CONTENT1\vs446515\labc\wwwroot\wp-content\plugins\all-in-one-seo-pack\[login to view URL] on line 766 Notice: Undefined index: aiosp_enabled in \\BNE3NAS2-CONTENT1\CONTENT1\vs446515\labc\wwwroot\wp-content\plugins\all-in-one-seo-pack\[login to view URL] on line 766 Parse error: syntax error, unexpected '=' in \\BNE3NAS2-CONTENT1\CONTENT1\vs446515\labc\wwwroot\wp-content\plugins\alo-easymail\[login to view URL] on line 331 I deleted the SEO plugin along with another plugin called WP Events Calendar and some of the errors went away. I added them back in remotely, but the errors came back, so this time I deactivated them via the WP-Plugins panel. Those error have now gone away, but really I need them as they make up important features of the site, plus I sill have the following errors: Notice: attribute_escape is deprecated since version 2.8! Use esc_attr() instead. in \\BNE3NAS2-CONTENT1\CONTENT1\vs446515\labc\wwwroot\wp-includes\[login to view URL] on line 3303 Which appears all over my live website [login to view URL] Also in the wp-control panel I am getting the following eror message: Notice: Undefined index: page in \\BNE3NAS2-CONTENT1\CONTENT1\vs446515\labc\wwwroot\wp-content\themes\thearchitect\functions\[login to view URL] on line 125 I need a freelance who has a brilliant understanding of Wordpress and PHP to fix this quickly!