Report Filters Using Zoho.Loginuserid

I'm building an app for client tasks. I've got one form to track company information and another to track company contacts. The contacts form contains a multi-select lookup field of companies. If a company is in that field, the user should be able to see its information when they're logged into the portal.

Initially, I thought Great! I can place filters on reports so users only see information/tasks they've been granted access to using lookup fields and zoho.loginuserid!

So I created a Client Dashboard page. Here are the major problems:

I place a report widget in the page. If I have a savvy customer that uses the menu and changes the report view - to kanban, for example - and sorts the columns by company name, every single company in the database shows up even though filters are in place. Report criteria doesn't flow this far down.
I place a report widget in the page. There is no option to eliminate the "View As" menu function. There's not even an option to hide the menu bar.
I publish the report and embed it into the page. I can hide the menu function but can't restrict view by loginuserid since the report is public and viewer information is irrelevant. Therefore, clients will see all database information.

I have had no success thus far using parameters (I don't even know if those will work for my situation). I've come to these dead ends after chatting with Support. Is there any way to actualize my requirements where:

Loginusers can see all information for the companies on their profile and that's it, regardless of what buttons they click?
There aren't a million reports of the same form to maintain?
There is minimal ZML/HTML to write/maintain?

It seems as if this shouldn't be a problem. My mind will be absolutely blown if there's no way around this.

Thanks in advance!