Is html, java, css are important in professional field when approx every company use WordPress for develop their Web page

Answer 1

Yes. Only small businesses use wp. When you move up to corporate companies and/or get paid to fix websites written in html you must know this. Also, i have been paid to fix the php, css on wordpress style editor so its still important in wp

Answer 2

Nope

Answer 3

Yes you need them all to develop with WordPress.