Wordpress Modifications and Host Migration

Ideally looking for a UK based freelancer for this.

I have two sites I need help with, the tasks are as follows:

1. Rewrite the image files en masse for these old posts,

the images in these posts link to our old URL, e.g:

http://www.OLDURL.com/wp-content/uploads/2013/05/blabla.jpg

If the word "OLDURL" is changed to "NEWURL" it will work but I dont want to do it manually.

2. On the second site - we have a CDN setup, but apparently the CDN sync tool we are using to setup the CDN is returning some errors. This may be related to a new host we have been using (who are terrible) but it may be that there is some error in the setup.

What I need is for you to diagnose the setup, work out if its done correctly and with speed and best practice in mind, then fix if necessary. Here's an example of the errors apparently being given:


[29-Oct-2013 05:51:52 UTC] PHP Fatal error: Call to a member function syncFiles() on a non-object in /home//public_html/wp-content/plugins/cdn-sync-tool/cdn-sync-tool.php on line 86
[29-Oct-2013 06:52:24 UTC] PHP Fatal error: Call to a member

And the plugin is called: CDN Sync Tool

3. Transfer two sites

I have two sites, on two separate hosts, I need them to be transferred to a new Hostgator VPS host account.

Currently one is on Site5 shared hosting, the second is on a different hostgator shared plan/account.

For this I'd like to use a staging URL on the new host, so we can see the sites functioning before we update the namservers. Had a real headache with hosting this past couple of weeks.

4. On both sites there is a "popular posts" sidebar widget, it's based on how many comments a given post has received rather than any useful metric of popularity.

Can you amend it so that it shows the top viewed post by number of views or visits for the past 7 days is shown top?