Very difficult indeed. The easiest way would be to record a faucet running on high. Don't know of any software that creates the sound of water ... so the best would be to simply download some good waterfall sound effects and import into your project.
Splashing
idkkkk Get a digital handheld recorder and go through every room in your house recording different actions to make household sound effects, like door slams, kitchen sound effects, light switches, etc. Household sound effects are one of the most common type of sound effects.
Yes ,I guess so Definitely, they are often used to make cartoon sound effects. See the related link.
a waterfall
Bound
a waterfall
jk
with the computer sound effects and sometimes with mouth effects
Waterfalls. Rain.
There's always sound effects. Sound effects tend to get stuck in (your) audiences' heads.
sound effects
Roaring and smashing.