Earlier quoted context omitted.
From what I read in the article, you need to also avoid signing anything that says you’ll sign something else later (why in the world is that kind of contract legal?).
Your question makes a mistaken assumption about contracts. Contracts are not "legal" or "illegal", they are "binding" or "non-binding". And a contract that stipulates that you will sign something else later is generally non-binding. The people who ask you to sign such contracts are counting on you not knowing that. There are several criteria that a contract needs to meet in order to be binding. Interestingly, being w…
Yes this is true, although most jurisdictions impose fairly low upper limits on the amount of consideration that a verbal contract can cover. As of 2012 the most common value was $500 or less (and probably is still the same level or close to it in most areas). Anything involving consideration valued at more than $500 USD was not binding unless written.