Hi,
You can disable zoom in sppagebuilder, by selecting your layout page it could possibly by the name 'Products', and on that page you see an addon placed on the very top left. Edit that and under Sellacious Tab you can select the option to disable Zoom. See Attachment for more clarification.
And we have introduced enable/disable zoom feature natively in sellacious global configuration also from v1.5.3, but if you have customised sellacious then it's better not to update sellacious by yourself.
Thanks