How do i include a "bigger" image (on left/right) on the survey, and other questions related to image?

Hi @Athirah Welcome to the community! To help answer your questions: 

1. The images in the form are resized according to where you have placed the image, but it isn’t possible to make them any larger unless you change the layout of the questions. You can read more about image sizes here. 
2. If you’re obtaining the images from our media gallery, these are royalty/copyright-free. :) 
3. We don’t necessarily have a way to ‘stop’ a survey, but you could add a logic jump that would prevent them from moving forward in the form if they don’t agree. 
4. There is! If you have our Business plan, you’ll have access to live chat. Otherwise, you can contact our support team via email here or pop by the community, too!