I dont really have much to add to the drop-d tuning other than, when I first got my guitar and was chatting with an instructor at a local shop, he told me to not drop tune. Learn the guitar with it's natural tuning first. Makes since to me.
As far as the tone controls? I just replaced the pickups on my guitar and when I did, i completely removed the tone control and replaced it with another volume control. I never used the tone control, so for me it was useless. I'd rather be able to have independant volume controls for each pup.
Having said that though, there are probably lots of folks out there who do like having tone controls. If you're tone controls don't seem to be working perhaps there is something not wired up correctly or maybe the control itself is not working.
Good luck.
[U]Ricks Current Mystery Video[/U] - Updated Monday March/02/2015