Supplications

No problem.

You can continue and repeat after the athan in your heart if you are in the toilet.

The Prophet salla Allahu alaih wa sallam said: Whoever sees a person who is afflicted with some trial and says, ‘_Al-hamdu Lillaah alladhi ‘aafani mimma abtalaaka bihi wa faddalani ‘ala katheer mimman khalaqa tafdeelan_ (Praise be to Allaah who has spared me that with which He has tested you and has favoured me over many […]

This is authentic.

If you don’t hear the actual athan, you shouldn’t say it.

The wiping is done after reciting the last three Quls. These all should be said while in bed before sleeping.

There isn’t anything special dua to my knowledge only general duaa.

Yes

La ilaha illa anta subhanaka inni kuntu minathalimeen