Hello Crunchy,
AVADirect is a system builder, meaning we actually do not manufactuer the parts we use in our custom configurations. These manufacturers, such as Gigabyte, make the decisions on what BIOS to use, and the types of features to use in them. My guess, Gigabyte decided to switch to the American Megatrend BIOS because it's popular, and known to be quite stable compared to other BIOS versions.
Gigabyte should have their own software that provides those gimmicky applications you've used before; if you go on the Gigabyte website, they might have Windows software that will allow you to tweak some BIOS settings within the Windows interface.
It's not that the AM BIOS is better, it just make have more benefits that other BIOS versions may not provide for Gigabyte boards; or, the BIOS might be known to work better with Gigabyte boards due to the chipsets they decided to use.
We always provide the remaining thermal paste purchased by our customers. You paid for an entire tube, so why would we keep it? Anyone those knows the properties of CPU/GPU heat transitioning and basic application of thermal paste knows that it takes very little (a pea sized amount) to ensure the best results when attempting to have the best cooling possible.
Thank you so much for your kind words! We work very hard to provide the highest quality builds available today. I'm very happy to hear you're so satisfied with your purchase! You're always welcome to post any questions or concerns you have on our forum.