Try getting rid of the “0” key in your tax_query and meta_query array.
$query_args = array(
'post_type' => 'post',
'post_status' => 'publish',
'order' => 'ASC',
'orderby' => 'none',
'posts_per_page' => '100',
'offset' => '2',
'page' => '2',
'tax_query' => array(
array(
'taxonomy' => 'post_tag',
'field' => 'name',
'terms' => array('test'),
'operator' => 'IN',
),
'relation' => 'OR',
),
'meta_query' => array(
array(
'key' => 'post_title',
'value' => 'test',
'compare' => 'LIKE',
),
'relation' => 'OR',
),
Also in your first set of args you have 'category' => 42, but this should be 'cat' => 42,