Sorry for the delay in responding and thanks for the thorough replies, your work on my board and the inclusion of the bypass caps.
R.e. the connector pin offset issue; I was wondering about that. When I was looking for connectors I noted the associated text for some through hole 2.54mm connectors stated the pins are offset to assist placement (by a tiny 0.005 inch). I made the foolish assumption that the images I saw in the PCB view were a representation of the offset.
R.e. starting in one view; for the relay board I posted, I started in the breadboard view which for some reason completely exploded (and created the wiring errors) while I was working on the PCB view. Am I correct in thinking that as long as the PCB view is ok, then I don’t need to redo the breadboard?
Following your advice to build the circuit in one (schematic) view, I have been making up some “practice” boards in the schematic view (a 12 relay board and a LM3886 amp). I have to say (to any Fritzing novices reading this) that this is a much better approach.
I have had a look at my boards in a few online (free) gerbv viewers and they appear to be ok. However, there are lots of them and because the manner in which each one operates can be quite different I am wondering if there is a/are “preferred” gerbv viewer(s)?