The original link I posted was in reference to Photoshop not Elements. I believe (but am not certain) that this level of feature has been around in all Photoshop versions after CS5.
The original article explains how Photoshop can be used almost immediately by anyone with Photoshop skills on video files. So layers, Adjustment layers, levels, filters etc can all be used. These skills are readily known to existing
Photoshop users. The gist of the article is that if you have at least basic photoshop skills, you can "learn" the video editing skills with minimal additional effort, as the program and its features are already well known to you.
I have Photoshop 2014, and my version lets me open MTS files quite happily. The link below shows the list of supported file formats - this link is from Adobe's help site.http://helpx.adobe.com/photoshop/using/supported-file-formats-photoshop-cs6.html
As you will see, MTS is listed there, and the asterisk against it simply adds that the support for this format was introduced in CS6.
So if you have CS6 or later, according to Adobe, the MTS file should be capable of use. I suspect however that MTS file formats however do vary by camera manufacturer - BUT
Adobe do NOT list any caveats angainst the MTS format. I do seem to recall that Sony MTS format may have had issues, but I may have this wrong.
Worth checking that you are using Photoshop with all updates (and not elements), and then try Adobe's help sites if you are still struggling