Component as Plugin

Can we create a plugin i.e. for our own tmyTable, tmyQuery, tmyDatabaseConnection?

So we could create a plugin for mysql, postgresql etc and our users can use the needed plugin to use the database. What we make is to create 

tmyTable = class(tmysqltable) or tmytable = class(tpostgresqltable) in our bpl...

Would this be possible with tms-plugin-framework?

Yes but it will require some work to define the interfaces that will expose these databases classes from plugin to host app.

In plugin demo 3, see the example that uses such interface to expose a plugin tab to a tabsheet.

Is it possible that the demo's are not installed in latest version of TMS Plugin Framework?

The demos are normally deployed under \My Documents and there should also be a link added in the Windows start menu