Hi,
1 – 2. The results page design and fields are fully controlled by the theme you are using. These have to be managed via the theme, the plugin cannot affect that, it is not possible.
3. Yes, you can do that under the Theme Options pane.
If you want a different layout (horizontal, isotopic) with a different template, then you can load up a template: https://i.imgur.com/ajXC1ml.png
..or you can change it as well for the existing tempalte here: https://i.imgur.com/oZIgjtw.png
TIP: if you are switching to an isotopic layout (without switching the template), then turning off the result description field usually gives a nicer layout: https://i.imgur.com/08UIn8i.png
