No, single report can use single query.

Can I possibly combine multiple SQL Queries into a single report?

I want to know if I can have 1 single master site that has all content. Then I want to have multiple child sites with with different members/administrators who can edit content for that specific site, and put into categories that will be displayed on the master. The master ...

... have own tag and you will use 'Tags -> Tagged Items' menu item instead of 'Articles -> Category Blog'. But note that displaying same article in multiple domains is considered by Google as duplicate content.

No, you can share only all K2 items, all iProperty data and all Zoo data.
Please also note that MightySites doesn't clone or transfer database data, it shares it, so multiple sites use same database tables for certain contents.

New features: ⋅ Allowed ordering by multiple fields. ⋅ Allowed tags in HTML processing of column value. ⋅ /* IF NOT tag */ conditional element. ⋅ /* IF tag = ’test value’ */ and /* IF tag != ’test value’ */ ...

... search options for own search and content plugin search. ⋅ 'Terms Columns' setting for Category layout - allows display of terms in multiple columns. ⋅ 'Alter Glossary - Category' module to display terms with lots of settings. ⋅ 'Terms List' - display a list of ...

... will use users database tables of main site, so all sites will always have same users. 1- Can I control the SlaveSite user access via the "multiple-profiles" feature in JomSocial? Sorry, but I don't know if JomSocial profiles allow any permissions. I think not. 2- Can I set-up a SlaveSite, ...

... that ALL users would be shared - all, or nothing more or less. My questions are; 1- Can I control the SlaveSite user access via the "multiple-profiles" feature in JomSocial? 2- Can I set-up a SlaveSite, sharing other component files and data from the MasterSite but NOT from Jomsocial ...

Joomla uses favicon from template folder or root folder, so actually right now it's not possible if multiple sites use same template.

But we can add a custom override and you will be able to setup favicon for each site separately, please create a ticket in out support center.