These three are the ones that are image related, so I took a look myself at your site:
1. Specify image dimensions - F (0) - 51% - Images - High
2. Optimize images - F (21) - 73% - Images - High
3. Serve scaled images - F (43) - 90% - Images - High
Most of the problems are not ones that EWWW IO can take care of automatically for you. However, it appears that some of your Ads on the left side are stored in the /uploads/ folder which is a good indication that a 'Bulk Optimize' (under the Media section in the dashboard) will be able to take care of #2 for those images.
Optimizing the rest will be a bit tricky, but you could upload them to the Media Library, and then overwrite the originals in the plugin folders and elsewhere. The plugin images will further be complicated by the fact that they will be overwritten next time you upgrade that plugin (like the Social Slider images). Your best bet there is to contact the plugin author and ask them to optimize their images.
That takes care of #2, which is the only thing this plugin concerns itself with. However, I can give some insight into some of the others:
#1: again, most of these are related to your ads not having image dimensions set, but it looks like a lot of these may be served by plugins. If they are, you'll need to contact the plugin authors to see what they can do. If the images are ones that you inserted yourself, you can go into the html code and set the proper dimensions there, which leads me to the last item...
#3: Nearly all of your front page images (left-side ads, center slider ads, the blue buttons near the bottom, and even the 'feature' images for each article) are being viewed at a smaller size than the actual image the browser is downloading. As an example, the left-side ads have been edited to 85 pixels, but you've told the html to render them as 75 pixels, which means everyone who visits your site is downloading nearly 25% excess image data on just those images. The blue ones at the bottom are worse, and then center ad slider is not scaled properly either. This plugin looks like it might help for some of those: http://wordpress.org/extend/plugins/simple-image-sizes/
I would suspect that many of the errors under #1 would go away once you took care of #3, so it may not be as daunting as it first appears. If this is all a bit much for you, I could take a look, but I don't do that kind of work for free.