Is there a set of drills I can use to get a good measure of my overall ability?
The Pool Quotient (PQ) ability test, based on progressive practice drills, is a good tool to measure ability and track improvement over time. Here it is: PQ Ability Test. Other self-assessment info can be found here.
A better system for determining and monitoring a player’s level of ability is the Billiard University (BU) rating system. It assesses a wide range of important pool skills in a methodical, thorough, and consistent way. It also provides a numeric and descriptive rating. The BU rating comparison chart shows how the BU rating correlates to other commonly used rating and handicapping systems.