Nice overview! I would add that as a start, you can now join AngelList as one of those individuals contributing $1000 in each deal (that the leader of the AngelList Syndicate puts together). This can help build a concrete track record of making returns on your own money.

Also, in the US, a law was recently passed that is opening up investment opportunities to non-HNW individuals. Sort of crowdfunding for equity stock as opposed to products/perks as kickstarter has been doing for years. This can lower that $1000 you would need on AngelList to even less. Example here: https://equity.indiegogo.com/