This is not a copy pasted hollow bid, so please read it. You will find all the information you need to take a decision right now.
1. I can install one of this two contributions:
Ultimate Seo Urls 5 PRO(for 2.31), or ULTIMATE Seo Urls 5(for 2.2).
This might take a while depending on how customized your site is...
2. This seems to be an easy 3 minutes fix... No problem.
3. Google XML Sitemap SEO install and configure no matter the version you are running. I will also load the CRON for this to run automatically.
Little note, you dont upload to google, but provide information in webmaster tools so that their robot visits and indexes your site...
4. Remove "Advanced Search", easy.
5. Categories layout will require a little more time, I can do it properly with jqwery, in my sandbox, once you approve, I can upload it to your site.
6. Complete htaccess, crossbrowing and sql injections + site monitor install and configure, so you get a completely secured site. I also recommend to move the admin folder and to set htpassword protection aswell.
So as you can see, this is a professional approach. Also is my work. I really understand your requirements and, as you can see, I know what I am talking about. This bid will not be the cheapest, sorry for that, your list will take some time to be done. I will not require escrow for the amount of + comments you have...
So, that's it. Thanks for reading this and please, I encourage you not to hesitate, get this done properly the first time. You will not regret it.