Hi there
With Toolset you can make templates for your custom posts to display your custom fields either using Views Content Templates (at Tooslet > Content Templates) or using Template Layouts (at Toolset > Layouts).
With most themes, both do the same thing, which is to replace the content area of the page when viewing single posts with the content generated by the template.
The main difference is that Views Content Templates are simpler, you just add the markup (and insert shortcodes for custom fields) directly into the template.
Layouts is our page builder where you can drag and drop content in cells which are laid out in a grid you choose.
Otherwise they are essentially the same, so the answer to 1 is Yes.
The slider cell available in Layouts is for displaying a "static" slider, which is to say that you choose the images you want to include from the Media Library, so that the same images would be used on every page that uses the Template Layout.
If you want a "dynamic" slider, where the images to be used come from your posts' custom fields, there are now 2 options.
If you have a repeating image field (i.e. a custom image field where several images can be added to the same post) then you need to manually enqueue a slider library of your choice and then generate the markup in the format required by the slider. I wrote detailed steps about doing that here: https://toolset.com/forums/topic/how-to-display-the-pics-i-uploaded-as-a-slider/#post-518295
However, there is now a simpler option.
Make a repeatable field group for your images (that contains an image field and perhaps a text field to use as a caption, too, though it can just contain the image field itself).
Repeatable field groups create child posts that act as containers for each group of fields attached to a post, which means that you can then use the built-in slider functionality of Views described here:
https://toolset.com/documentation/user-guides/creating-sliders-with-types-and-views/
Such sliders transition between posts (rather than between images of the same post), but because of how repeatable field groups work, you can create a View where for the content selection you choose the repeatable field group in question, and then you add a Query Filter for the repeatable field group to identify which post the images will come from.
Do you want to try that and if you get stuck let me know.