There may be a longer family history here where support networks got burned - two most common I've seen are drug use and mental health issues. Criminal justice involvement much lower on list.

For transitional job programs - you don't get kicked out w out a reason - they work with lots of people. They agree not usually as ocial workers though - program is about jobs and employers usually.

Ok to use them for mail like onboarding paperwork from employers. Because of liability and other risks (folks can be hustling etc still) usually not ok too use mail service for other reasons.