[Libreoffice] Bug 38811 - [EasyHack] default to SQLite not HSQLDB in Base

I am interested in writing the SQLite driver code for Base. However I have
some questions (that a fellow Base driver developer might be able to help
me resolve) with regards to what actually needs to be done, and how it
needs to be done. Keep in mind that I am completely new to LibreOffice C++
UNO coding, and there doesn't seem to be any guide for Base driver writing
or using UNO interfaces.

* What classes/services/interfaces at a minimum have to be implemented? I
browsed through the drivers tree and it appears that not all drivers
implement all services (except for some basic ones such as tables and
columns). How does one decide what to implement and what not to implement?

* Are the code skeletons for the drivers usually auto-generated or written
by hand? There is some documentation for generating code skeletons from
UNOIDL files on the LibreOffice SDK API page but I don't know if that's
relevant to this case or not (once again, driver developers can let me know
what they did).

* Are there any existing unit tests for testing Base functionality with new
drivers? If not, how were the existing drivers tested?

* (a simple one) How will I set the default driver to SQLite in the source
code?

Thanks in advance.
--Mohsin