Towns & Resources, always very poor when new?
I've found that whenever I takeover a new territory, all the external sites (towns, mines, farms, ports, etc.) are classified as Very Poor. I've also found this to be the case when new towns spring up. Thus, I usually only build things that don't have a property value (schools, churches, etc.).
Do the classifications ever improve? Like, if you keep developing your town hall building, will the towns go from Very Poor/Meagre to Poor/Low to Average/Growing etc.?
Re: Towns & Resources, always very poor when new?
Some technologies improve the wealth of towns. Since the conquered territories probably aren't as developed as you are, it will take time (and upgrading buildings) for them to become wealthy.