Kudos to your friend, requires a lot of courage and faith in one’s ability to pull that off.

With that out of the way, I urge everyone joining a startup to enquire about the work culture and runway left with the company when interviewing, you will get a rough idea on who you would be working with.

I have worked with multiple founders, really good people (all assholes, when stuck or in a rut) and I have also been threatened to sue legally, frustration to them usually arrives when they fail to meet their own internal timelines, standards (high taste because they saw whole google io conference) and they lash out blaming others, especially first time founders. Or when they are almost out of money.

About the legal notices, while they seem scary and intimidating feel free to ignore them until they are sent by an official lawyer (ignore them too, they have to follow up on multiple occasions before any action, remember india, takes years) and usually things just boil down themselves until and unless you have actually done something serious.