If I update a price on a Service or Material, does it automatically change the pricing on previous/old Estimates, Jobs, and Invoices?

Easily update pricing without affecting pricing on previous Estimates, Jobs, and Invoices.

No. If, for some reason, you need to change an old invoice/job/estimate to reflect new pricing, you would need go into the old invoice/job/estimate and select the newly-priced service/material, then save the invoice/job/estimate again to update it.