@GuruXtreme

On a straight road with no traffic, speed upto 45kmph, pull the clutch and leave the accelerator.
Can you feel any kind of vibration at handle bars and foot pegs ?

Please check the chain slack at the tightest link of the chain.
The slack should be 1 and a half inch (1.5") Anything less than that - the gears will not slot properly and the bike vibrates even when coasting with the clutch pulled in.
This isn't a splendor where one can tighten the tappets and chain too much and get away with it.

An experienced mechanic can easily distinguish between the vibration caused by rattling body parts/panels and engine-transmission related .
In extreme, all the body parts/panels have rubber grommets where it attach to frame and they do not vibrate.

After you reply to this message, I will tell you how to solve idling rpm and other issues.

EDIT:
Check this post by Sibun. He has explained chain adjustment, rear wheel alignment and centering in a very simple language.
http://www.xbhp.com/talkies/do-yours...tml#post872728