Bugs in code

I’ve bought a theme from themeforest and installed it (after updating wordpress to the last version).

As I imported demo-content, I started getting this:

Deprecated: Methods with the same name as their class will not be constructors in a future version of PHP; WP_Import has a deprecated constructor in …/wp-content/plugins/wordpress-importer/wordpress-importer.php on line 38

Deprecated: Methods with the same name as their class will not be constructors in a future version of PHP; OrangeIdea_Twitter_Widget has a deprecated constructor in …/wp-content/themes/newera/framework/widgets/twitter/oi_twitter_widget.php on line 33

Deprecated: Methods with the same name as their class will not be constructors in a future version of PHP; OrangeIdea_Flickr_Widget has a deprecated constructor in …/wp-content/themes/newera/framework/widgets/oi_flickr_widget.php on line 33

Warning: Cannot modify header information – headers already sent by (output started at /…/wp-content/plugins/wordpress-importer/wordpress-importer.php:38) in …/wp-admin/post.php on line 197

Warning: Cannot modify header information – headers already sent by (output started at …/wp-content/plugins/wordpress-importer/wordpress-importer.php:38) in …/wp-includes/pluggable.php on line 1167

Should I contact the theme author or can I fix it somehow myself?