I started to sign up for Predictit and there was a note that any money deposited is charged a 5% withdrawal fee. Maybe that effects the odds since people who would be placing accurate bets factor the withdrawal fee into their potential winnings.
Point 4 said a slightly different way: when you rent you are arguably shorting housing since you need to live someplace. When you own 1 place you are neutral and you aren't long in housing until you own multiple places.
Two things to keep in mind when you are making your choice:
1) Exercising isn't a binary decision; you can exercise a portion of your options (ex) exercise 40% and leave 60% on the table to expire. This lets you factor in your personal financial status when you are deciding on your course of action.
2) Many series C startups don't fail or exit. Once a company gets to that size it has a momentum of its own even if it isn't successful. In my case I've worked at 4 startups. Two have exited while the other two are still stumbling along. I left one of the stumblers over 15 years ago so they can go on quite a while!
I am not sure if this would come under the umbrella of financial terms but a discussion of different ways companies can be valued would be interesting. My understanding is that in addition (or instead of the traditional PE ratio) some people use free cash flow. Also other people look at EBITD, and other metrics.