Question is whether it'll be financially / commercially viable. I think that greatly depends on how much data the telescope gathers or whether it needs more time. Also keep in mind that the Hubble got multiple upgrades over its lifespan, which will be much more difficult with the Webb - is it feasible to do spacewalks that far out? Has any astronaut ever done a spacewalk outside of Earth orbit?

Are you referring to the protection by Earths magnetic field?

If so, would it matter much, given we (allegedly) shot humans in not more than slightly pressurized tin cans to the moon multiple times?

And they survived.

Yeah, if it has done it set out to do, then we don’t need to. Also depends how much of a moon presence we have in five years. Launching from the moon might make it feasible for sure, considering the billions the JWST has cost!