I'm looking for Help sharing files with a client which is a Bank!

I'm looking for Help sharing files with a client which is a Bank!

Let me start by saying Zoho seems so cool for a small business. I'm hoping someone can take the time to share ideas with me.

So I handle inspections for many Banks and the banks do not have the ability to click on notification e-mails linking them back to zoho to retrieve or download a file. To avoid paying a lot of money creating a business solution to handle all this for me, i've tried setting up a shared Workspace and Group in Zoho Docs which I hoped would work. We generally share .xls files and in the past have been e-mailed these including updates etc. It appears zoho should be the program to help this process. I was also hoping I could share comments and updates about the status of inspections through this program somehow. 

Issues- 

1. Is there a way to limit the amount of work "ie creating accounts" the Bank would have to do to get on and download these reports? The Bank would obviously use a username and password to gain access. I feel like if I can set that up for them it would work better and be more professional. I found when I set up a shared workspace or Group this required the Bank to have their own account and then I couldn't actually download the files. 
2. Is there a way to communicate using zoho about the inspections that they would receive updates on. Or do I need to still use e-mail for all this as in past?

Sorry if this is totally confusing to someone. But any help would be appreciated.