1), 2) It’s possible by additional customization. Use child theme if you plan to make any changes in template files. Child theme archive you can find in theme package. If you don’t have necessary skills you can order our additional customization service https://www.8theme.com/customization-services/
3) It happens once, after first child theme activation. This is how WP works, child theme is like a new theme for WP and sometimes widgets could be messed up after child theme activation. As a rule, this should not affect Theme Options but if you faced this problem do the export (Theme Options > Import/Export > Options > Export) and import these options after child theme activation.