Ok, now the tricky bit - draw a polygon (button looks like a piece of paper with top left corner torn off - click a corner follow the perimiter of the board, must finish up where started or will get "illegal poygon" error or similar), name it GND, on both sides of the board. Your thru holes will connect them. Click the Rubberband button, and let eagle connect everything up to GND. May even be to "ripup" the ground traces.
can add a mating connector alsohttp://www.dipmicro.com/store/KLDX-0202-Aor screw terminals in parallel with the pins you appear to have now.Add +/- labels to the Vin pins so you don't accidentally miswire them.http://www.dipmicro.com/store/DG126-2PCheck the size of the holes. These look Phoenix brand.
Which are the pins for the Rx module?
Stop mask errors are inherent in the design of symbol parts - its like outline markings that go over the pads on connectors. No way to get rid of them. Its things like Clearance Errors that you have to worry about."The reason for this is because it is maybe going to be powered by a 230V > 5V usb adabter."If that is the case, the 7805 as wired now will only be in the way - adding a way to bypass the diode & regulator when Vin = 5V would be needed, otherwise you will not be getting 5V to the board. Alternately, make the unused 3rd pin Gnd, and use that as 5V source to other things when using Vin >7.5V. Ok, I see you add that in a 2 of the 3 pictures.Its fun,isn't? Like electronic puzzle solving.The ground planes look good. You would tweak a few lines here & there & let the planes fill in the bigger white spaces that are there.
Once you get the hang of it Eagle is really powerfull and friendlier than it seems.