Good stuff.

You're right about the equity part of your pay. Don't count on it to pay your bills. Between the stock / options / RSUs / whatever they grant you and liquidity lie several snares:

• Most companies that get to liquidity don't do IPOs, they get acquired. Are there some obvious companies out there that might want to acquire this startup if / when it becomes successful?
• How long is the "runway" for the company? How long until they need to either get enough customer revenue to sustain themselves or until they need another round of financing? Followon rounds of financing often reduce the value of options by dilution.
• Do the founders / executives really want a liquidity event? Do they have investors pushing them to sell? Or do they want to just keep running the business? The execs of profitable startups are often happy to just keep doing their thing, and won't feel pressure to sell. (Selling or IPOing is a huge pain in the xxx neck and can be far outside the skill set of operating executives.)
• Is their a barrier to entry for the product? Or can some megacorp simply copy what you do and reduce your value to zero?