How do I start if I don't have a specific niche?

Initially I follow a course that tell us to start posting youtube shorts, repurpose/remake videos of someone else, then use blackhat method to spam link to our youtube shorts, and the youtube shorts can either talk about a product, or a course, then put affiliate link in the pinned comment / descriptions.

So I'm thinking if I'm going to do that, might as well as start a proper youtube channel for long term while also try building affiliate income from the very begining and maybe I can post videos about my journey in making money online, which is kinda broad because I'm going to try doing different things, starting business, selling service, doing affiliate, even doing blackhat method, etc.

So I want to ask people already have experience:

1. Can I start a youtube channel with broad niche (money making - affiliate, sell service, ecommerce, dropservice, investing, even crypto), then go specific later? (For example in later when I have success in affiliate marketing i will be fully talking about affiliate)
2. Does spamming my youtube video link directly via tools like GSA website contact posting into website's contact form, going to get my channel penalize or banned?
3. What are some thing that I can do to promote my channel at the beginning instead of posting video for less than hundreds view and pray for algorithm to promote it?
4. Do you think I can make a channel profitably without showing face?