Not necessarily
Because the second floors ac unit`s drain line is either terminated above your utility room or the primary drain is now plugged and the unit is overflowing into the space(above your utility room).
The difference between a gully trap drain and a floor drain is placement. A floor drain is in a floor, a gully trap drain goes on an external wall.
No.
Floor is sloped toward floor drain for draining. Floor cleanout is level with floor and is used to clean out drain line.
A floor drain , drains water and other liquids that spilled on the floor
You need the water to be overflowing.
The drain from the washer to the main line is getting plugged and the floor drain is easier. Drain cleaner in the floor drain should take care of it.
Shouldn't be a problem. You may need to extend the pipe at the sink a bit to put in air vent so that the drain can vent. It is a checkvalve that lets in air when the sink drains. Or you can tie into the existing vent stack if possible.
Try hydrogen peroxide to kill germ causing bacteria
Not much other than the floor slopes into a flor drain so any water or other fluid goes directly into it while a floor sink is bigger, sometimes has a strainer in it but pipes can be ended directly above floor sinks so that the fluid from the pipe flows pirectly into it
You would have to build a platform for the tub to sit on. About 3 inches if you are using a floor drain. There is a trap right after the floor drain so you would not need one at the tub. If possible you could position the tub directly over the floor drain but that would eliminate the floor drain which would be a problem if the basement every flooded.
The toilet flange is usually above the floor level. You would have to cut it off the drain pipe and cap it. How you do this depends on what type of pipe the drain is made of. Even if the drain should be below the floor level, you have to seal the drain or sewer gas will come up from the drain.