Marrying "a good person" can also mitigate all those concerns you have. If two "good people" co-habitate then neither one will just leave after 20 years. Overal

Marrying "a good person" can also mitigate all those concerns you have. If two "good people" co-habitate then neither one will just leave after 20 years. Overall, advice about "good people" isn't really actionable.