Is it legal for a tow company to enter my car to remove an expired parking sticker and then tow my car?
The booklet from the condominium management could legally be seen as a part of the lease, and you should have been aware cars can be towed without notice, and have in fact agreed to that by living there.
The fact that the tow company entered your car really isn't relevant; they are tasked with removing the car, and by law, they must do everything they can in order to tow the car while not causing damage. They will be insured and bonded for damage during the tow and liability for storage at their lot; but in order to safely tow the car, they must have access to the parking brake, the gear shifter (if manual), the steering wheel (to straighten the tires, if needed, which could be a problem if the steering wheel is locked), etc. They can legally enter the car to ensure a safe tow if the car is unlocked, or use a "slim jim" or other tool to unlock the door, disable the alarm if needed, etc.
If the tow company damaged the car while towing, or you find property is missing from inside the car when the care is returned, your issue is with the two company and not the condominium management.