Issue with missing resource (maybe to do with New Child Theme?)

Hi,
Right so earlier today i created a child theme for a site that had alot of CSS Modifications on it. Now im trying to speed up the page loading time related post - https://premium.wpmudev.org/forums/topic/website-load-speed-general-performance#post-921812

After Following the comments from Adam, and installing the plugins / changing settings etc. (hopefully setup correctly) and re-running some tools.PingDom.com tests there are several resources that are missing,
1. my_style.css?ver=4.2.3
2. codemirror.css?ver=1.0
3. new?sccss=1&ver=4.2.3
4. my_style.css?1437833598
5. admin-ajax.php?action=wordfence_logHuman&hid=CEA2C5CC96A8541EEA09D0B04E15073A&r=0.7088160656858236

each of which are taking few seconds minimum to load. and by the looks of it not finding the resources.
here are expanded screenshots of each issue
- http://www.awesomescreenshot.com/image/435019/b68ae28d155f5041a0ee5455324329ef
- http://www.awesomescreenshot.com/image/435020/7d52f5558d4dcdd796307ffa569d5d09
- http://www.awesomescreenshot.com/image/435022/87874b80a26913a1b437dd4f44e929d4
- http://www.awesomescreenshot.com/image/435023/cc1555f2948b2bb8cc7259144bba056d
- http://www.awesomescreenshot.com/image/435025/29cd32556d283a9b8f2340b414e7b663
-
Please feel free to run another pingdom test (please ensure that the test doesn't go public by unchecking the tickbox >> under "Advanced" >> "Save test and make it public" <-- Untick this! for more detailed test results. domain is: http://tinyurl.com/lguqz6p

I tested from the Amsterdam, Netherlands options as main site users in UK.

from what i can see in the path of the missing files it looks like they are trying to access My-style.css files in the child theme under a directory that doesn't exist (perhaps as it did already exist in the main theme directory before) but as there is already a My-style.css file in the child theme i wasn't sure if i should copy that one into the same path directory or move the one that its looking for from the original theme? or something else ??

Please can you take a closer look for me please?

I have extended support access to Support access is ACTIVE until July 28, 2015 9:10 pm

(please dont post any Images / Brand / Domain links etc here please use
http://tinyurl.com/ for links and http://www.tiikoni.com/tis/ to upload temporary images with links ) - this is due to google finding away to link brand name to wpmudev posts which is really annoying and causing multiple issues)
Thanks

Tom