I installed the mobile module and I'm currently using blackcandymobile as my mobile theme
Is there a way to include codes?
I'd like to limit the number of children to be shown in the mobile version
Should I create new templates for each page?
What is a good way to do this?
I'm not really understanding the question. What do you mean by "a way to include codes"?
you can edit the templates in the blackcandymobile theme any way you want. If you want to use custom functions in your mobile theme just add them to your .php classes in mysite/code.
I'd also recommend looking into responsive web design as an alternative to using the mobile module. It can be argued which method is better (responsive vs dedicated mobile) but imo, responsive is the way to go.