retro has already given u the answers.i wud just elaborate the points.
1) DO change rimz to alloys.as the original 13inch rimz get deshaped easily nd wud ruin the comfort of ur car nd will also loose value if u want to sell the later on.tyres i wud suggest u to go for dunlop le mans 701.a very nice tyre in reasonable price i.e. 2500rs per piece.
but i wud say dnt exceed 14inch size.it wud make the ride more bumpy.city already has a hard suspension. the exact size u shud get for idsi is 185/65/r14...this wud give u almost the same diameter as of the original tyre.
2) yeah it is compatible wid cd changer or player but its better to get rid of this thing.its just very annoying.so do change it.
3) which lamps? fog lamps...? depends...if u r in mood of spending sum 2.5k to 3k rs...then go for them.otherwise,not nessessary
4) dnt know wats trptronic meter(tell me plz)...hav heard of optiron meter.its only thoeratically possible i guess.dnt mess wid it i wud say.
5) yeah sure get cng,idsi is very fuel efficient but still,a normal person cant afford petrol.as the international rate is expected to rise to 200$ per barrel soon.but get cng frm a good mechanic.try to get a lightweight faber cylinder.landi renzo kit,advancer nd emulator.if u need performance nd hav 15k extra lying around,get lambda oxygen sensor too.wud considerably increase performance.
6) as u live in rawalpindi,it wud b better to get one.cuz in there is a greater risk of theft in larger cities.but do get insurance for it.its must these days.its very unlikely that u get the car stolen(allah na karaY) but very likely that i hit it sumwhere everymont(again,allah na karay)
i think that wud all b helpful for u...thanx.