Clore Bros. Canoe Outfitters, you have gone too far. Shorts should have long inseams so that they will stay under your harness. Lose fitting shirts or tank tops should be worn as well. Your shoes will have an affect on your climbing performance. For climbing, try to pick a pair that fits very tight.
Running shoes are bad because they have such a wide foot platform for stability.
A pair that has a snug fit and are able to get dirty are the best choice. You may want to bring an extra pair, more hiking boot style, to wear for the approach to the crag. Bring a lunch that you can hike in and eat at the crag, and a minimum of one quart of water - no glass please. Camera, Lip balm, Sun screen, Insect repellent, Sun glasses, or anything else you may want to have in your pack for a day out.