Lyric discussion by yossarian9 

Cover art for Bag Lady lyrics by Manic Street Preachers

Firstly the title refers to someone who is homeless. (Bag Lady) 'Eternity is not sunrise' may I believe relate to this short William Blake poem 'Eternity' -

(He who binds to himself a joy Does the winged life destroy; But he who kisses the joy as it flies Lives in eternity's sun rise.)

Since this is rejected it is not lived in, without a home.
What can we associate with a home? healing/sanctuary/safety/boundaries/authority These are all dealt with in the song and shown to be unstable (health-'flowers die'/self-'ruined me'/laws-'paper burns')

As for Richey, I hope he's leading some kind of monastical/nomadic life somewhere :-)