Having a SaaS with open source code is possible, but probably best to consult with an attorney to insure the license being used is going to match up with your business plans.

I have seen a similar process on some open-source blockchain projects where they just award people who fix issues within the code.

You could use AGPL and offer an additional commercial license, which is what Artifex does with Ghostscript.

A restrictive license will restrict adoption. Don't expect much help until there is traction

What do you mean with adoption?

It means companies will not let their employees use software licensed with restrictive or uncommon licenses, even if free, they are automatically red flagged. So you immediately eliminate a large and profitable segment users.

Thanks!