These water stains are evidence of water penetration around this chimney...this is not uncommon.

The 1/2 inch gap between this rafter and the ridge beam could be evidence of a number of things.

Although this looks disconcerting it is typically caused by an inadequate vapor barrier...
and not a cause for concern. 

Though difficult to see here, these stair step cracks may be a problem if they appear in conjunction with other evidence.

The brown caulking shown here is being used to conceal a gap that has developed between
the brick and mortar.

The soil around this foundation should be graded away from the house to promote consistent moisture levels and reduce the chance of foundation problems.

Federal Pacific brand panel boxes and circuit breakers have a history of past failures, so their performance should be monitored and an electrician's advice may be advisable.

Believe it or not the moisture retained in this roof edge is supporting plant-life!

These ducts should not be laying on each other or on the attic insulation. Doing so can generate condensation that will mat down the insulation, reducing its efficiency, and possibly stain the ceiling sheetrock below.

Openings in exterior walls such as this one used for A/C lines, are an open invitation for pest infestation and moisture penetration.

Look closely below the deteriorated siding, an exposed anchor bolt is present. It should be cleaned of rust and resealed with epoxy.

We noticed some water penetration in this trim board and probed a little farther. A licensed pest control technician confirmed it...termites.

Installing weep holes at the bottom of this brick wall would help moisture behind the wall to escape, and assist in air flow to keep it dry.