Portsmouth can be a great place to be, no doubt. Pet friendly, and as you've discovered, a great vibe. Check out
South Church | A unitarian universalist congregation for more info for the non-denominational church you are looking for.
You might also consider Dover, sort of a 'Portsmouth-light' in that there are walkable areas of downtown, plenty of locally owned businesses, etc.
If you're considering venturing even further down the coast, into Massachusetts, Newburyport MA also has a fun, but more upscale vibe. Very walkable downtown, like Portsmouth is on the river and makes excellent use of the waterfront area (festivals, etc)