Increase title size Placement

Is it possible to increase the size of the titles used on each post? I would like to increase the size without having to change the overall css for the site.

Yes. Use a plugin like “Better custom CSS” and paste this code into the input area of it:
.rpwwt-widget ul li a span.rpwwt-post-title { font-size: 2em; }
Instead of 2em you can use any other font size value you like, e.g. 24px, 150% etc.

Also is it possible to have the title above the image and excerpt?

No. That plugin does not offer any position changes. But you can achieve this – and more – with the plugin Ultimate Post List Pro.
You can take a first look at the free version Ultimate Post List.