Pki secrete engines - Request certficate for webserver -does it required csr as a parameter

1.Does the pki secrete engines has a provision for csr as a parameter for the web-server certificate ? as i saw in the docs it accept only cn=www.example.com

2.if i am disabling the PKI secret engine, does the vault environment have any side effect ? since the vault communication over the tls. or is it managing separately.