New Champion Idea

I don't really know what I'm doing so if you would like to add suggestions I would love that but I just thought that maybe a champion like this should be made:

Name: Dr. K. Boom (pretty crappy name I know, feel free to think of another one.)

Position: ADC Weapons: A bazooka and a mortar.

Passive: Oily Manner: Dr. K. Boom's attacks are powered with gasoline which causes abilities/passives that light the target on fire to deal +10%/+20%/+30%/+40%/+50%/+60%/+70%/+85%/+100% damage. Stacks 9 times. Eg. Ignite, red buff, Brand's passive, Brand's E Conflagration

Q: Rockets / Thrusters / Shell Launcher (can one key even do 3 things?)

Rockets: Loads and launches large gasoline-powered rocket in a straight line for 35/45/55/65/75 (+100% of AD) damage. This applies 2 stacks of his passive instead of one if it hits a target. Cost: 30/40/50/60/70 fuel. Spell Range: 1000 units (little under Ezreal's Q Mystic Shot). Flight time: 1 second. Cast time: 0.75 seconds. CD: 9/8/7/6/5 seconds

Thrusters: Once the first Q (Rockets) has been launched, you can activate this at any time during it's flight time of 1 second to increase the damage, range, and speed of the rocket. Cost: 15/30/45/60/75 fuel. Range increase: +100/200/300/400/500 units. Damage increase: +10%/+20%/+30%/+40%/+50% of original damage. Flight time remains the same but since the range increases the speed must also increase. CD: 9/8/7/6/5 seconds

Shell Launcher: Once in mortar mode, every time you press Q you launch an explosive shell in a 300-unit (~Aatrox's basic attack range after his ult) circle. This shell hits all enemies in the AoE for -10% of actual AD per enemy champion before armor is applied. This also applies a stack of his passive. If this lands on an oil bomb (W), it ignites the ground for 10% of enemies' current health true damage. The burning duration will last as long as the oil bomb stays on the ground. Cost: 10/15/20/25/30/35 fuel. Cast time: 0.5 seconds. Range: 1000. CD: 1 second

W: Flameout / Oil Bomb

Flameout: He increases his AS by +10%/+15%/+20%/+25%/+30% for 5/6/7/8/9 seconds and his basic attack damage by +25% for 5 hits. He then can't shoot for 3/4/5/6/7 seconds. Cost: 10/20/30/40/50 fuel. CD: 15/18/21/24/27 seconds

Oil Bomb: Dr. K Boom shoots an oil bomb that slows all enemies for -20% MS. This applies 3 stacks of his passive. This stays on the ground for 3.5/4/4.5/5/5.5 seconds. Cost: 50/55/60/65/70/75 fuel. Cast time: 1 second CD: 14/16/18/20/22 seconds

E: Mortar / Bazooka

Mortar: Switches to Mortar mode. In mortar mode, Dr. K Boom can't move. Cast time: 1 second. CD: 1.5 seconds.

Bazooka: Switches to Bazooka mode. Regular basic attacks that apply 1 stack of his passive. for every unit killed with a bazooka shot, Dr. K Boom regenerates 4/6/8/10/12 fuel.

R: Piloted Ultra Rocket

While in mortar mode, you can use this ultimate.

Piloted Ultra Rocket: Launches a rocket into the air from your mortar which has a range based on your current amount of fuel. 1 fuel = 30 range. At lvl 18 with max fuel, you have a range of 6000. You take control of a massive rocket which takes 3 seconds to descend onto wherever you right-clicked. Once it hits someone, it deals 150/300/450 (+160% AD) in an AoE. This applies 3 stacks of his passive and burns targets hit in the inner area of a 500-unit circle. It will deal 90% damage to anyone in the outer circle of 750 units.

Sorry no TL;DR.

So tell me how crappy/not crappy this idea is.