Will coated chicken fry up ok if not fried right away

Once fried chicken or any fried food for that matter is refrigerated it is going to lose it's crispiness. This is due to the cruncy exterior coating absorbing moisture from inside the food combined with moisture being trapped inside the wrapping/storange container which then is absorbed by the food as well. It happens even shortly after frying if the food item is placed on a flat surface where the inner steam can't escape and is trapped between the food and the surface under it. This is why when frying large batches or holding fried food for any extended time, it's best to drain on a cooling rack that's upside down on a brown paper bag or paper towels. Upside down so that it's close to the paper to absorb excess grease but still allows a small bit of airspace so that steam can escape and if keeping it in a warm oven, hot air can circulate.

You can re-crisp your chicken by placing it on a roasting/cooling rack on a baking tray and place in the oven to re-crisp the skin. Be careful not to dry it out.

Panko won't stick to chicken (too dry), but will stick to egg. Egg won't stick to chicken (too smooth and non-absorbant), but will stick to flour. Flour will stick to chicken. Dredge first through flour, then through (well beaten) egg, then through panko. It's a tricky combination, but if you do it right the results are excellent. Any dry spices you want to put in can go in the flour. While I don't know for sure, I would certainly wouldn't include any oils in the coating, as none of flour/egg/panko will stick to oils.