Thanks for asking a challenging question. I don't know. Historically most systems of popular representation have excluded them. I assume for reasons that made sense at the time. I guess I'd rather live in a country that had universal franchise + the means to escape these people's gravitational well. Rather than a country that disenfranchises them albeit for solid reasons. Basically you try to build a stronger engine rather than to reduce drag. These people are here and they're not going anywhere. We have to somehow make our shared world work. It's a large and difficult problem and most people really dislike talking about it.
Absolutely. Being a victim of repeated scams isn't a crime. These people need help and ideally to be given tools to use to protect themselves. They don't deserve disenfranchisement.
Should these people be eligible to vote?