Great feedback, thank you all. Let's see if I can hit all of the questions first:
@smartalec: Yes, this is an LED controller driven directly by ethernet and driving 64 channels.
@budude: I was going to compare/contrast this to DynamoBen's PropController, or maybe jstjohnz' E680/681, but it is optimized for one purpose and therefore much more application specific.
* DesignSpark does have DRC capability and I did run it. There were no spacing violations, but many "pad to silkscreen", "via to silkscreen", "track to drill hole" and "annular ring too small" (on the RJ45 jacks only) errors. I haven't fixed them yet because I don't know that the design rules I used are correct in the first place. I'm using the DesignSpark default technology file and rules that came with the tool. I have to figure out where to get real, official DesignSpark technology files for SeeedStudio. While I can't imagine having to code that up myself, I felt the same about component libraries until I gave in and created all my own components. So while there were no DRC track spacing violations, given the feedback that may be due to incorrect rules in the technology file I used (default).
* Good comments on the common ground. Each RJ45 does drive 8 individual channels. The GND on this controller board also needs to be brought to the distribution boards for each channel. Generally this will be "for free" because they will share a common power supply (+5V and GND). However, I did provide for the case where the controller board is powered by a separate supply; that's why there's a third terminal on the power connector (upper left corner) to provide for a GND wire out. I would have prefered a 9P9C RJ45a jack but my searches for that failed...
@LabRat: You nailed it. In my original post I stated that I was amazed at how long this takes to do (well). I already have 10x more hours into this than I anticipated. What you see here is the result of the many hours it has taken me to go from all components placed in a heap off the board to now with the components all meticulously, manually placed, attempting to minimize trace length, congestion, crossings, etc. These actual traces are the work of the autorouter. I've seen areas where "I could have done that better by hand" but I haven't until I get some feedback that I'm at least close with the big picture (overall design, component selection and placement).
@ebrady: Aside from preference, are there pros/cons to the oval vs. round IC pads? I "borrowed" them from an existing library and have no idea if they are correct. Maybe I should use round because they are simpler to define correctly?
* The DRC called out "annular ring too small - size is 4, should be 5" on the mounting holes for the RJ45 jacks. I started with a component I found in an AMP connector library. This is just a common 556416-1 jack. The hole looks like it's defined as a pad, width is 0.136" and hole size is 0.128". I measured the tabs on the jack I have with a caliper and read about 0.12". I guess the complaint is that the copper around the hole is too thin after the hole is drilled (136-128=8; 8/2=4; 4 is width of the ring?) Is the copper ring needed at all? This isn't a pad, just a mounting hole. Does the copper ring provide some structural stability to the board where the hole is, or make it easier to insert/remove the jack mounting posts?
* I absolutely do intend on a copper pour on the bottom layer, for GND. My protoype design is working, but I have SI issues that are causing glitches. No wonder, with all the wires running around in space and the long lengths and no decoupling caps. I've been obsessing with the decap placement (based on advice from others) and as you see the only way I could have gotten closer to the PWR/GND pins would be to open the IC package. I hope that a GND plane will help me here also.
So the outstanding issues (aside from manually routing, or at least fixing, the traces) are:
1) How/where can I get a technology defintion file, with accurate design rules, for DesignSpark & SeeedStudio? I'll be searching after I hit "submit" on this post.
2) What is the "correct" hole size to accommodate through hole pins that are not actually round, or even those that are? For instance, I'm using a Tyco/TE 1-390261-4 (datasheet here: http://www.te.com/catalog/pn/en/1-390261-4) I read it as saying that the pins are 0.024" x ??", and use a 0.039" hole. What drill size is that (if that is correct in the first place)? What size pad do I need to define for this?
Thanks for all the responses. I'll get there, although it may take me a few more passes.