Changing user attributes (Sync passwords) - Office 365 Exchange Onpremisses (Doubts Part 3)

Hello friends,

I will separate my doubts in parts, so that the posting will not be too large.

I have a cloud environment that will synchronize with my active directory site and I know I'll have to have an exchange onpremisses to change the user attributes that are synchronized.

All users will now sync exist in Exchange Online and in production.

I know I can sync first and then install Exchange, but will have to update the schema ad connect. But I will first are installing Exchange Onpremisses AD Connect already be configured properly.

However, do the following questions:

1 For I see Office 365 users in my Exchange On-premises (Exchange 2016) I need to create remote mailboxes, right?

2 That I do after the enable password synchronization, right?

3 - I can create remote mailboxes using the EAC? Or only for PS Exchange?

Please, I'm not deploying a hybrido environment. Some cite issues about this scenario, but it is not my case.

Thank you.