1.) Two trigrans confront you in a dark alley and try to force feed you a strange green algae 

Hahano, they'll learn why people don't mess with the Ford.

2.)A grumpy dwarf that has one ear sells weapons in the sewer.

Look through his wares and pick the decent ones, haggle the price and buy them.

3.) Rashaq. That's all I need to really say.

What? They're not doing anything so there's nothing to be done.

4.)Racist Yanar with a broadsword 

Probably tell it to go bug someone else and come back when it's not trying to commit a crusade.

5.) A man in a red vest gives you a purple flowers for no reason and leaves

Thank him, smell the flower, then tuck it on an ear because people gotta be fabulous sometimes.