Of course, you're right, the reason why these scripts and files are loaded is caused with the Social Locker plugin because it creates the social buttons which are used for unlocking content.
But it's a normal situation for the case when you use any social buttons on a page. A lot of millions of sites show social buttons on their pages. And every of them loads these scripts.
Yes, the social buttons will make your page a bit heavier and slower but it is acceptable. You should not worry about it.
Also please keep in mind that these scripts are located on social network servers that use all modern technologies to provide fast access for files placed there such as caching and CDN.
The reason why the analizer site thinks these files are slow can be explained by the fact that it doesn't use special caching headers in its http requests to the facebook, twitter, google servers in order to assess actual transfer speed of loading without caching.
You can ask this question on stackoverflow.com and I sure that you will get the same answer as I provided.