Thanks, that sceenshot helped me a lot actually. I've made a modification where if the step is lower than 1, it automatically switches to 2 decimals. It should be enough in your case as well.
First of all, make sure to have a back-up copy of everything, before you change anything.
Then open up the wp-content/plugins/ajax-search-pro/includes/views/asp.shortcode.custom_fields.php file, and replace it's contents with this: https://gist.github.com/anag0/a375e3e4e48f2a33cce44080bcac039b
This should fix the step and the label decimals as well.
2. request: Well, that is not possible unfortunately. I've tried to look for tweaks of whatnot, to maybe somehow allow it, but unfortunately I can't recommend any short modification to make this happen, I'm sorry.
3. For custom designing consider custom CSS first. If that is not enough, then there is the reults templating available – but be careful not to change up the structure too much (instead add elements), as it may lead to script errors.Best,
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