Learning leaguestarting bossing. Zero to hero training. with questions

Hi. I want to expand my knowledge about the game and want to try and understand bossing on leaguestart. I have a few questions.

1. Whats usually a good leaguestart bosser and how do you go about progression, are you zhp and play very careful or do you swap to zhp later on (if you go zhp)

2. What is your go to boss / way to make currency early on. I assume most of the currency comes from voidstone carries?

3. Im thinking of creating a fresh account and doing a full zero to hero where i pick a bossing build and try and recreate a league start scenario, anyone got pobs, tips and tricks

4. With the introduction of nightmare maps, is that something you consider when picking a leaguestarter?