The compression ratio will not noticably affect the idle. The cam affected the idle. A "performance" engine is a compromise. He gave up a smooth idle and low end torque and in exchange, got top end power. A different cam profile could make a great idle and low end torque. The cam is the single most important "performance" decision one can make on an otherwise stock engine. Raising the compression will just further cloud the issue unless more modifications are done, porting, exhaust, etc.

Leonard