Pros:
Simple To Pick Up
Great Scaling
Can Turn the Tide of a Game
Can easily stop waves from crashing
High Burst Damage
Can Save your teammates
Can Easily Chain Stuns with teammates to get a pick
VERY Fast

Cons:
Squishy
Hard To Escape without E
Vulnerable to CC
Requires High Positioning Knowledge
Only Source of Damage is a Skillshot
Requires Macro-Knowledge
Easy to Miss Clutch Ultimates

Combo 1:
Q + W + Q = Double Bomb, Most Basic Combo, Stuns enemy
Combo 2:
E + Q + W + Q = Slow Down Enemy, or Speed Up Ally to either make the stun easier to hit, or easier to chase a target
Combo 3:
E + Q + W + Q + E = Slow Down Enemy AND Speed Up An Ally to make the stun easier to hit and help them get on top of stunned enemy.

Tip 1: You can double bomb a minion an enemy to: get a bit more range than normal, catch the opponent off-guard, and pop the burst damage quicker.

Tip 2: You don't necessarily need to hit people with bombs to make them effective, they're also excellent zoning tools

Tip 3: Stay back in team-fights, if you get picked off early you wont be able to make use of Chronoshift, or your stuns

Tip 4: Your Q has a quite lenient hit-box and you can hit people just barely on the edge of it most of the time when you think you'd miss

Tip 5: Don't always use W after using one bomb, if you can't hit the next one, don't bother, and save the mana.

Tip 6: Don't ult too early.

Tip 7: Bomb + Ignite op op

Tip 8: Don't get caught out doing random **** too often.

Tip 9: Don't be afraid to shove the wave once in a while no-one's around or coming for it and its about to crash, easy gold and exp for you, and it helps the team.

Tip 10: if you save someone with your ult, make sure to throw a stun or an E their way to help them get out, especially if enemies are around.