But in what way do you mean constrain and manipulate? By simply existing, any moral rule constrains and manipulates moral sense. There's no exceptions, regardless of the source of that moral rule; be it religious or laic.
If on the other hand you mean religion has done more wrong than good to the moral sense, despite all my ranting I cannot agree either. Religion still is a bastion of morality. I can agree it is rapidly loosing its appeal and being replaced by better institutions for several reasons, one of which the issue at the center of this thread. But with very few exceptions, any religion in the world is centered around moral canons. These define them. And objectively, these are good moral rules.
I do not look into morality as the source of religion's "evil". Religions are fundamentally good at their core. That evil I see instead in religious doctrine and especially dogma.