I'm new to composites. I'm doing a wing that is just over 1 foot in wingspan. There will be no core, so it is 100% solid carbon fiber...joining both halves with a 1mm layer of very high strength epoxy and chopped/milled fiber.

I don't need torsional strength at all for this part, I need strength from tip to tip so the wing doesn't snap in half.  My plan is to use mostly  Intermediate Modulus(830 tensile 43 Modulus) UNI directional 12K 8oz/300g for the skin or surface layer.

I don't care about appearance, so is  UNI directional okay for a skin layer?

If each half requires 10 layers of fabric should I vacuum bag each layer with the first 5 layers and then rough up the surface and do the other 5 layers as a secondary process? A rep at the composite store said this may be a preferred method? Below is the pic of a generalized layup I have in mind....thanks in advance.

Peak exotherm is important because you want to avoid a run away if you're doing a thick laminate. Building too much thickness in one hit can cause the heat build up to get so hot that you get uncontrollable shrinkage, potential cracking, and possibly damage the mould if it cant take the temperature. 

Honestly, 10 layers of a 300g uni is not really that thick, so this shouldn't be too big a worry for you. But using a slower resin system with a low exotherm is a good idea regardless. By all means, apply heat AFTER the exotherm has died down again.

For me personally, with the resin systems I use - 15 layers in one hit is no issue. However it may be an issue with your materials and equipment, so I would always recommend doing a smallish test first.