Why Britain would strike ships in harbor

Would the Royal Navy attempt Taranto-style attacks against German ships?

Yes, because harbor attack was a long-standing Royal Navy doctrine supported by specialized shallow-running torpedo techniques.

Attacking ships in harbour was a long-standing Royal Navy preference. Taranto applied that approach with torpedo arrangements intended to keep the initial dive shallow. The explanation describes tension on a wire at the torpedo's nose helping it enter flatter, limiting how deeply it plunged after release. Plans also existed to attack German ships in port, but finding the targets remained essential. Better aircraft and more carriers could expand the opportunity in a delayed war without guaranteeing a target or a successful attack.