I can drop using my backhand, but the question is.. do you just touch the shuttle when you do the stroke or do you slice it like how the forehand does it?
I do both. I slice it sometimes, but I just tap it most times. This is for the straight drops. For crosscourt drops/smashes, I have to use some wrist power/wrist flick to do them.
slicing, almost always. But then, my backhand drop solution mostly comprises a "just bash it" approach... (sorry for the interrupt, but I'm assuming you're on the defense, or getting pushed into a corner... If you're the one putting pressure on people, you should hit backhands ) The reason being, no matter how tight you drop, it your drop is slow, you're still in trouble. If you whip it, landing it half court, but get it reasonably tight over the net.... Your opponent can't kill it, and might have some difficulty keeping you under pressure...
I have a question, when backhand slicing drop, do you slice completely horizontally? or do you slice 45 degres or 30 degrees towards the net?
I'd say pretty much square to the net... But that's guesswork, I honestly couldn't describe it... Though be ware, most sliced backhands are hit at head/shoulder-height, just watch the pro's. Backhands hit at higher heights (stretching your arm slightly) aren't sliced a lot, maybe a little... It's a whole technique; with grip, positioning, hitting technique and timing... I couldn't possibly put it in words... I'm no Gollum
No. Backhand smashes are rarely a good get-out-of-trouble shot. Your best chances of recovery usually lie with the drop shot. But your drop shots should be fast, landing at the short service line or deeper. A slow drop shot gives your opponent far too much time, and enables him to play a tight spinning net shot.