This is caused by negative pressure in the drainage/sewer system which can suck the water out from the toilet bowl. To prevent this from happening you must fit an Air Admittance Valve or AAV close to the toilet but above the overflow height of any nearby wash hand basin. The AAV allows air to enter the drainage system to neutralize negative pressure caused by flushing a toilet or letting the water out of the bath etc.
You probably need to replace the wax ring and possibly tighten the two bolts that hold the toilet to the floor.
No, but you might have a problem changing the floor flange 90 degrees so that the toilet could be clamped down again.
Sure. Either way. The wax ring seals the toilet to the closet flange so it doesn't really matter that much. The important part is that the toilet be mounted firmly to the floor so that it doesn't move. That would cause the wax ring to fail then the toilet would leak around the flange.
The knobs on the bottom of the toilet hold the toilet to the bolts that in turn hold the toilet in place on the floor.
Yes As long as the flange does not hold the toilet off the floor it will be fine.
No,you can get sick the next time to wipe
heater core leaking
Yes that's what the flange sit on and get bolted onto that is why if you remove the toilet/flange you will see a hole in your floor
The floor around your toilet and sink could be hot because there is a heat vent nearby. There is no specific plumbing reason for this.
You may have to remove the toilet from floor and look underneath. Things usually jam where toilet meets floor flange. Takes about an hour for a competent handy man to do.
Yes. Typically the comode is cauled where it meets the floor.
The toilet seat.