Yes, a molly is a fish.
Mollys can breed with any other type of molly fish
There are many different types of fish. A "painted" Molly fish, refers to any Molly fish that has been dyed to appear as "painted" with markings.
Molly fish do not lay eggs. They are livebearers and give birth to fry fish. If there are eggs in an aquarium with Molly fish, then they belong to another fish.
Yes.
Yes, molly fish do have gills.
no i have black molly if you have guppes thay will go with it and otherr fish
No.
Human... Or predator or bigger fish.
A fish eater.
It seems so as my Molly flirts with them but ignores the female guppies
Yes, I have had lots of experience with Oscars. One of mine died recently from a sickness. Algae eater fish are not dominant, in this case the Oscar does not take it as a threat and does not bother it. The answer to your question is yes, an Oscar can live with an algae eater fish.