You've got a solid motherboard for overclocking, not sure about the cooler though, haswell gets pretty hot if you increase voltage, so be careful with rasing vcore. Provide more details on the cpu cooler, is it a heatsink or AIO cooler? Also word of advice never strees test on Adaptive or Auto mode, always do it in MANUAL MODE.
here's a thread on overclocking
This is for Asus ROG boards, but same will apply to your Asus Deluxe.
http://rog.asus.com/242142013/labels/rog-exclusive/maximus-vi-series-uefi-guide-for-overclocking/