Should I use an ORM like SQLAlchemy for a lightweight Flask web service?
SQL Alchemy is generally not faster (esp. as it uses those driver to connect).
However, SQL Alchemy will help you structure your data in a sensible way and help keep the data consistent. Will also make it easier for you to migrate to a different db if needed.
I'd rather just use raw MySQL, but I'm wondering if I'm missing something besides security concerns.  Does SQLAlchemy or another ORM handle scaling any better than just using pymysql or MySQLdb?