Yes because it is a new paragraph.
Yes, you indent each new paragraph.
No, you do not have to indent each time someone speaks in a dialogue. You can simply start a new line with the speaker's name or dialogue tag to indicate a change in speaker. Indenting is one way to organize dialogue but not mandatory.
Horizontal Ruler
Certainly, so long as the rest of the paragraph pertains to the dialogue. You can describe the character's actions and thoughts. Once you move on to another character, though, you need a new paragraph.
Hanging Indent
yes you should because it is the beginning
Yes, Dialogue should be like a conversation. It needs pauses and punctuation, so in each time the speaker changes you start a new line and indent.
An indentation should be exactly five spaces.
each time you press what key does word carry forward to the next paragrapgh
No... you just have to indent a paragraph once. If you need a tip just take your finger next to the line that you have to indent and that should be the amount of space that you indented.
The first line of each paragraph should be indented to create a clear visual separation between paragraphs in a written document.
Yes.