Confused about Push Data to CRM

Confused about Push Data to CRM

Hi, we're setting up our first mailing list and I'm a bit confused.  Here's our situation:

1.  We're using our Zoho CRM "Contacts" list as our primary mailing list (we have around 5,000 contacts that we have imported into Zoho from our old system)

2.  We do not want to use the Opt-in / Opt-out field in CRM as it also restricts just sending the person regular email.  Also, we have four different newsletters that people can subscribe to, so a single opt-in / opt-out field is inadequate.  

3.  We have created Push Member Status as Fields for both Email and Autoresponders in both the Leads and Contacts Modules in CRM.  Although I don't know why we need them in both modules.  

4.  We have mapped data fields under Push Data to CRM under both Leads and Contacts.  Again, I don't know why we did this as we only want to track subscriptions in our Contacts module and not in our Leads module.  

I have two questions,

1)  If we only want to sync fields back to our Contacts module, then why do we also have to map them to our Leads module.  

2)  How do we create a web form that captures leads and subscribes people to our newsletters at the same time?  We want to create an online profile database so they can update their profiles in the future, but from their first contact, they should be able to select their subscription preferences.