I haven't found any clear resources online to be able to figure out what makes any web test truly dyslexia-friendly. I hope you guys can share valuable information here.
If I could give you a simple and direct answer for each widget you mention then there'd likely be a Stylesheet or tool already available to yield those results, it turns out that this is not an area where there are not definite solutions. Ultimately, people suffering dyslexia determine whether an interface is dyslexia-friendly or not (and then you have to differentiate if their feelings are rooted in dyslexia | normal usage | personal opinion). You may also need to compromise between dyslexia-friendly solutions and other solutions given other constraints (such as Accessibility for the vision-impaired, who require (via legislation and standards) high-contrast, while dyslexics tend to respond better to lower levels of contrast).
Here's an article discussing design for dyslexia: https://www.dumblittleman.com/dyslexia-website-accessibility/