yes
no
No.
Tapwater.
Yes, goldfish can survive without food for two days.
No you mook
Goldfish
Goldfish are freshwater fish and can not survive in saltwater environments (oceans, etc) They can only survive in freshwater (non saltwater such as ponds, rivers, and lakes).
Goldfish need water to swim and breath in, not mud. There are some species of fish that have evolved to survive in mud but Goldfish are not one of those species.
Goldfish can survive in a pond without a pump, but it is important to ensure that the pond has enough oxygen and is properly maintained to support their health and well-being.
It is possible that they may survive but not really likely.
It should be fine.
A swordtail is a tropical fish and a goldfish is not. The swordtail would need a higher temp. than the goldfish. Depending on where you live it probably wouldn't survive the winter.