Hi Bassam,
1)
This will very much depend on how much you spend on a quality host.
I would start by look at a cache plugin W3 Total Cache, then you could look at a CDN such as CloudFlare.
Have you got your performance settings enabled in the Theme Options => General Options => Performance options
2) They should supply you with the HTML/JS to embed on your page. Please take a look in the form setup or contact their support if you cannot find it.
3) Looks like your header banner is enabled. Please check it is disabled: Theme Options => Global Header Banner Options => Enable Global Header Banner.
4) They are the WooCommerce breadcrumbs, please add this CSS to your Custom CSS option:
nav.woocommerce-breadcrumb {
display: none;
}
Thanks,
David.