Peter and Old Grey -
Thanks again for the input. I have attached two files for review. One is the actual stereo jack plug showing the three pins and reinforcing legs that relate to the PCB. The question of the additional two pins that show up in the PCB trace which are not really there bothers me. The preferred trace would not have a hole where there is not a pin. Can I easily delete the unneeded hole in the "stereo jack", or does it really make a difference if the trace has a hole in it? I can think of several ways to create the same pattern ... but that would involve three copper pad holes (or "vias") in the proper spacing as well as 5 drill holes in the proper size and spacing as well.
As for the power connnector ... the one I am using is a part from Adafruit or Sparkfun ... not sure which, and the legs do not seem to require a hole any larger than the 1.2mm hole that is standard on the Adafruit perma proto boards. I can not tell what the size of the hole and ring are using the default power connector in the core parts database, but it visually seems much larger. For that matter, as I understand more of the process, I do not know what the default hole and ring size for the "jumper pads"
are. Perhaps either of you know or could explain how I can determine that. The "vias" default is 0.4 mm hole or 0.9 mm for "home etched".
If I understand the suggestion for the "bypass" capacitors on the LCD board, it is to minimize "noise" perhaps created from the AC conversion to DC at the power connector. Since the MKR1000 has capacitors in place (I assume) ... the need to add them on the LCD board is just extra caution, or am I not clearly understanding the need for them? I have not had any formal training in electrical theory or engineering ... I am just a competent "handyman" who likes to tinker. I appreciate the challenge to understand when and when not to include components in my projects. Every time I try something new, I learn something.
I am attaching two jpgs for review. Thanks again for the wonderful support and advice.