Jainism has more influence than it has followers. Is it a positive influence?

Jainism offers a path to escape the cycle of birth and death, along with a detailed cosmology that distinguishes it from Hinduism. For example, they believe in an infinite universe that progresses through a 40,000 year cycle - during half of the cycle, our fortunes wax, and they wane during the other. Right now, we're a bit past the top and headed for a long ride down. When things are as good as they can possibly get, children are born as twins so that the male and female can both be fully realized. All creatures have souls, but a human incarnation is necessary in order to transcend the cycle of rebirth.

No, it just leads to error.

I can only speak for myself. Jainism is against all killing. The most devout practitioners do not so much as wish to kill a plant for food. Something they do is only eating fruit from a tree or a bush and in that way the plant itself may not be harmed. I find their philosophy to be too much but it serves to make me think. I contemplate and meditate on what is truth and I do wonder if Jainism involves truth. If more people thought twice about the killing and eating of meat from livestock they might think twice about hurting another human being. Jainism is a positive influence in that way.

I'm a Jain. Jainism has its origins and principles in Hinduism. This detailed cosmology, as you call it is from the Hindu Bhagavata. You have not understood the fortunes waxing and waning thing.

Hinduism also believes that all creatures have souls, but a human reincarnation...

And indeed, the founder of Jainism was a Hindu who sought to reform the religion. His main contribution to this sect was the emphasis on non-violence, which has been embraced by a large number of Hindus. Indeed, all Hindus who are anti-violence are Jains.