layout.haml

// I'd love someone to do things like answer the following questions:
// What should the general page layout be?
div.view
  div.navbar
    h1 Title
  div.content
    "Hello World!"
  div.bottom-toolbar

// What should the general layout of a table page be?
Simple tables can be made with lists
ul
 li
 li
 
 or with blocked <tables/>

// What should the general layout of an input page be?
ul.fields
  li
    label
      span.label "Email"
      input placeholder="Enter your email"
  li
    button "Sign Up"

// - What should the main elements of the tables be (e.g. how to display, page, edit, color scheme for rows, headers, footers, button layout)?
Sorry, not sure i'm right understand question...
The main things in tables are content and its readability & accessibility. 

// - What should the main elements of an input dialog be (e.g. fields, error messages, required field indicators)?
if you about user accessibility than main element will be label or input itself which help user access input methods

// - What should the color themes be? When should they be applied?
In general color theme for mobile should be limited to primary and accent colors, + greyscale colors. 
Can be choosen as 2 complementary colors for example or some other way.. That might be brand/ product colors for example.
This scheme should be applied through the whole app for primary elements/ branding and for accenting.

// Then how do those translate across the various platforms?
If you ask about design:
In case of hybrid app that might be same design for diffrenet platforms.
If you want create native look design for each platform we can apply platform's mobile styleguides 
keeping same color scheme and branding elements so it will look natively styled and consistent across all devices same time.