Schengen Visa, Please help!

I am travelling to Italy in July and I have an H1-B status with 485 pending. In preparation for applying for the Schengen visa,I have the following questions,

1) Do I have to apply for the Schengen visa in an Italian consulate/embassy
in person? Or I can use the help of a travel agency?

2) I have an Advanced Parol document, can I use that instead of an US visa
to apply for the Schengen visa and also to come back to the US?

Any insights/experience on this? Please help. Thanks!