everyone has their own style, i guess you just need to find yours. generally, i find that not rushing the serve helps improve accuracy. for singles, i do take a couple steps back from the service line because i dont want my serves to be long. but for doubles i usually stand at the service line to serve.
Relax, focus, and do your job. A decent (not perfect like the pros) backhand low/flick serve in doubles should be easily achievable if you put in enough practice time. A perfect one will take hours and hours of practice over and over and over and over again. A decent long serve in singles is also easily achievable after some practice as well. The service should be second nature to you especially since you will always be stationary doing the same motion over and over again, and should not be under any pressure(unless you give yourself pressure).
Well , normally i do this if my partner is weak . It seems to help. Deathsmash - It gives the opponents more time to react to the shuttle. Theirs many advantages and disadvantages. I would say it helps sometimes , but the best serve is to serve from the T.
For singles or as the man in mixed, yes. For level doubles, definitely not. ...and it also depends on the size of the steps.
I simply take a deep breath and exhale slowly, and I follow my stroke through in pace with my exhale, this sorta sets the rhythm of my serves and makes sure that they get nearest to the line as possible. Dunno if any of you tried that but it really helps me.
3 steps seems a lot, even for singles. as long as you're serving from a comfortable position, you should be fine. if you're talking about singles, also depends if you're serving backhand or forehand.