Clunking

Could be a bunch of things, the common ones are.
1. Shock inside the strut.
2. Strut loose or worn out bush
3. Lower control arm / ball joint / worn bushes
4. Sway bar mounting bushes
5. Sway Bar end link damaged or warn bushes
6. Debris stuck in the suspension causing the clunk.

The clunk over bumps could be any or all of the 5 items listed above. The turning left bit, would point me towards items 3, 4, 5, 6. I'd start with 6 and work in reverse order. 4 and 5 are easy weekend fixes. 3 requires special tool to separate the ball joint from the strut.

Simple tests
1. With the front of the car in the air, hold the tire at the 3 and 9 O'clock position firmly jiggle left and right (not so much that your turning the steering wheel). There shouldn't be any play or I should say very little almost not noticeable. If there's any play could be inner tie rod, worn steering rack (since the boots were replaced)
2. With the car still in the air grab the tire at the 12 and 6 oclock position and and firmly jiggle the tire up and down, there should be no movement. This would indicate a worn or damaged lower control arm.
3 if the above turn out to be fine, then a shock; debris or swaybar would be the next place I'd check.

Safe to drive?
First off, it's never safe to drive a vehicle that has worn or damaged suspension parts. That being said, it's best to know what is damaged; and only you can make that determination.

1. Check for debris stuck in the suspension, that may be causing the noise; debris can damage suspension components; as well as getting jammed to the point where the car won't steer.
2. Review the items above (keep in mind the list above is not a conclusive list, but are common)
3. If the sway bar bushes are loose or damaged, the vehicle handling will be compromised. Worst case the sway bar could fall off and get stuck in the suspension, or damage the car on it's exit from the vehicle; or come off and damage someone else or their vehicle.
4. Control arms are what hold the suspension spring to the wheel, and are also the pivot point of the suspension geometry. If they're worn or damaged. The steering and handling would be compromised. Worst case - the strut (wheel and assembly that hold it on the car) can come off creating damage extensive damage to the vehicle. I don't think I need to paint that picture.

Hope this helps.
M