thanks farhananwarkhan, the diggi sound in my case is due to slight "play" in the latch due to which the diggi has some kad kad, went to a suzuki showroom this morning to check if a brand new swift had the diggi issue that i have and found out that the new car's hatch does not have a play - so now going to take it to suzuki 3s again and get it sorted out
as far as plastic sounds are concerned, like i mentioned i have already opened the door and hatch trims and glued extra foam in places that might vibrate or have resistance, especially the sensor sort of thing in the hatch (under the trim) was a bit loose so tightened it with foam - this has reduced a lot of the sounds
i have driven my car quite carefully and have taken good care of it (IMO) and thus these little noises were hurtful but Allah ka shukar hai now i know whats wrong- the obnoxious sound coming from the passenger side door is actually due to the Rubber (not sure if its the rubber on the door or rubber on the frame) but i realized when i wash the car the sound goes away and after a day the sound re-appears, i was reading up on some international forums and found out that high temps make the rubbers go hard and one needs to lubricate them, thats wot i am going to do this weekend and Insha Allah my car will be back to normal with no sounds