Problemas encontrados com o Plugin BlackBox Debug

Pessoal,estou enfrentado diversos problemas de velocidade no site,desesperado busquei auxilio de todo lugar e achei esse plugin que dizem,achar erros e contar as queries geradas no site e tive uma surpresa:

Quando instalei a primeira visualização tinha 33,1 erros com o tema que uso,que é bem carregado.

Removi o tema e coloquei um tema básico para ver se persistia e fica o log abaixo com 12 erros ainda:

Strict (259)	is_a(): Deprecated. Please use the instanceof operator on line 392 in file /home/meusite/public_html/wp-includes/post.php
Strict (11)	is_a(): Deprecated. Please use the instanceof operator on line 498 in file /home/meusite/public_html/wp-includes/capabilities.php
Strict (3)	is_a(): Deprecated. Please use the instanceof operator on line 75 in file /home/meusite/public_html/wp-includes/functions.wp-scripts.php
Strict (2)	is_a(): Deprecated. Please use the instanceof operator on line 105 in file /home/meusite/public_html/wp-includes/functions.wp-styles.php
Strict (6)	is_a(): Deprecated. Please use the instanceof operator on line 160 in file /home/meusite/public_html/wp-includes/functions.wp-styles.php
Strict (12)	is_a(): Deprecated. Please use the instanceof operator on line 197 in file /home/meusite/public_html/wp-includes/functions.wp-scripts.php
Strict	is_a(): Deprecated. Please use the instanceof operator on line 37 in file /home/meusite/public_html/wp-includes/functions.wp-styles.php
Strict	is_a(): Deprecated. Please use the instanceof operator on line 115 in file /home/meusite/public_html/wp-includes/functions.wp-scripts.php
Strict	is_a(): Deprecated. Please use the instanceof operator on line 812 in file /home/meusite/public_html/wp-includes/script-loader.php
Strict	is_a(): Deprecated. Please use the instanceof operator on line 729 in file /home/meusite/public_html/wp-includes/script-loader.php
Strict (101)	is_a(): Deprecated. Please use the instanceof operator on line 205 in file /home/meusite/public_html/wp-includes/class-wp-error.php
Notice (3)	Trying to get property of non-object on line 597 in file /home/meusite/public_html/wp-includes/nav-menu.php

Peço e agradeço qualquer auxílio.