Since screens are mainly horizontal, you should design the sheet with landscape layout in mind.
The avatar is required on character sheets and crafts. You can use any id you'd want, but you need to specify the id used in the view attribute : "Avatar's id".
Color is required on character sheets. The id should be :
Display character level, race and class in My Characters manager
It is possible to display the level, race and class of your character on
its miniature in the
My Characters menu. To do so, use the exact
class ids respectively for the matching
components in your sheet.
You can also use the
class id on a component to display any
string of your choice instead, by populating it with a custom string.
You could for example use script to concatenate other fields than level,
race or class.
Some component have the computed attribute, which allow them to have a value based on maths operations and references to other components.
Beware that computed values can be CPU-intensive, so you should not use too many of them.