... site of my master site as a test Master site www.localtradeclub.com Slave site www.kent.localtradeclub.com I used kent_ as the database prefix and shared a few componants etc - nice thing of that is i can have unique content on the slave sites. Now my question - say i make a royal cock up and need ...

Yes, child site can be located in subfolder, but this should be a usual Joomla installation with its own files.
Zoo content can be shared.

Ok, then I have another question, to use my SSL it has to be on the primary domain so can a child site be in a sub folder without a separate domain?

and can Zoo content be shared?

The templates settings limitation is applied to Joomla 1.5 only, if two sites are using same Joomla installation and same templates.

Template width depends on the template itself, not on MightySites.

Yes, the data from AlphaUserPoints can be shared, we will add this option soon.

... possible as the template that displays in Facebook can only be 520px including the header and menu. Also, can the data from Alpha User Points be shared?