coolant issue sounds normal. the cluster gauge is worth less. you need to scan the temp via the obd2 port with the torque app or some thing of the likes to know what its really reading.

the coolant smell tho. you need to look into that. water pump can leak, the plastic elbows can leak as well, the heater hoses to the fire wall can leak too.

if you smell it in the car, then the heater core is likely leaking.

the ticking is a lifter. gm says its ok if goes away in a minute or two. oil change can help clear it up. mine would tick if i went past 3,000 miles on a oil change. change the oil and no more tick on cold starts. this engine had over 200,000 miles on it too.