The question is a bit broad, but I'll add my thoughts:

> I am doing the below steps to make website built with Magento is
> secured.
> 
> 1. security patches update needs to be updated frequently

Good!

> 2. HTML escape in all Inputs

Not good! This can even be counterproductive if used *instead* of the correct "sanitize input, escape output" method.

What you should do (and maybe you meant it like that) is escape all **output**. Even here, pay attention to context, `htmlescape` is not always the right choice. See also: https://magento.stackexchange.com/questions/569/how-to-escape-output-data/54768#54768

> 3. Create multiple user for different user (Dev, HTML, Testing, Live user) with different roles

Good

> 4. HTTP cookies in .htaccess

I don't understand that. Are you refering to the "HTTP only" cookie setting? If you don't need access to Cookies via JavaScript, that's a good choice.

> 5. X-Frame should be enabled in BO and apache configuration

Good. Other HTTP headers for better security are:

- `X-Content-Type-Options`
- `Strict-Transport-Security`
- `Content-Security-Policy`
- `X-XSS-Protection`

Read more about them: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers

> 6. BO admin path should be in a different domain or URL

Good, but if you put it on a different domain, also make sure that `frontend-domain/admin` does not redirect to that secret domain

> 7. Admin domain should be accessible only from specific IP's

Perfect, if that's possible for you.

> 8. If we add Load balancer then Session, cache, media storage should be added in centralized location, like s3 Bucket

Of course, but I don't see how it is security relevant.

> 9. If we add Load balancer then piece of code should be added in index.php for http termination Ref Link :
> https://magento.stackexchange.com/questions/14558/magento-wrongly-redirects-https

This is a dirty hack that should not be necessary. I recommend setting secure and unsecure base URL to "https" and create a redirect from http urls to https. Here's how to do it with load balancer and ssl termination: https://magento.stackexchange.com/questions/107083/redirect-all-http-request-to-https/107086#107086

> 
> Do I need to do any more steps to make sure my Magento website is
> secured.
> 

### Other standard procedures

- delete or protect `downloader` directory: https://magento.stackexchange.com/questions/16504/recommended-method-to-protect-downloader/98322?s=2|1.7138#98322
- make sure, the `var` directory is not accessible from the web, as well as `app/etc/local.xml`
- same for `.git` `composer.json`, `composer.lock` - if they exist. They should better not be deployed to production.
- disable execution of PHP in `media` to disarm malicious uploads
- Keep PHP itself up to date
- Review security of third party extensions, regularly check them for security updates
- regularly run tools like the [Magento Malware Scanner](https://github.com/gwillem/magento-malware-scanner) and magereport.com


There's much more you can and should do, especially when it comes to secure development practices. Do your research and remember: security is a process. You cannot "make the site secure" and then be done with it.

**Update:** I see, there's a duplicate with a more detailed answer https://magento.stackexchange.com/questions/61052/magento-security-punch-list