Walikum asalam Brother.
Nice to hear about your purchase.
Yes it hits the speed breakers because the ground clearance is very low. The ground clearance can be increased by increasing the size of tires. The best tires suited (according to my research), which will not affect the mileage much and will also increase clearance, are 185/60 R 15. You can put some good fuel saving tires like Michlen Energy saver. Sir, the tires in your ride might be worn out. I have often seen worn out tires in these imported cars. The ones in mine are also not in good condition. I dont know, weather these rides are imported with bad tires, or some one change these tires at Karachi port. Whatsoever the reason, if they are worn out, changing them might increase your fuel efficiency.
As far as the electric shocks you feel, well, this is nothing but simple accumulation of static charge. Sitting in the car, electrostatic charges are generated on the car seat and the person's body, due to contact and movement between the clothes and the seat. When the person leaves the seat, They take half of this charge with them. As they get out of the vehicle, their body voltages rises due to this charge. When they reach to touch the vehicle door, the electrostatic discharge and shock occurs as their hand approaches the metal door.
You can avoid the voltage build-up by holding onto a metal part of the door frame as you leave the seat. This provides a return dissipation path for the charge on your body.
This is very normal. You don't need to worry about it. Just put you hand on metal part while you leave the seat. Remove the hand when your contact with the seat finishes.
Well bro, I am not an CNG expert. People say that a four head engine can be easily fitted with the CNG. But the only problem which I see is CVT transmission. The CVT is a very sophisticated transmission mechanism and CNG can have very bad impacts on it. You can ask this question in CNG related section of pakwheels forum.
The only inference which I have deduced from discussion with experts is that CNG is not good for CVT Transmission. There is a version of 1.3 vitz available with 2NZ-FE engine. It is a four wheel drive ride. This version is without CVT. It is a simple 4AT Transmission. The experts say that you can have CNG in this version without any problem. But in CVT one's, it can be deadly.
Please ask this question in CNG related secition. Experts will guide you better.
Best of luck,