A: It's not necessary but it can be a really good idea. You'll want to address things like the equity split, vesting schedule, each cofounder's contributions (cash, IP, time, etc.), how much time each cofounder will be expected to spend (and if someone is starting out part-time, when they are expected to go full-time), and you may want to address consequences for failing to meet the required contributions and time - for example, company can claw back shares at original price and expel the cofounder.
A: You've identified several of the key items to include - project scope, responsibilities, timelines, confidentiality, and dispute resolution. You also want to outline how ownership of the project will be split, and how profits/revenues will be split. Will you be forming an LLC to carry out the project? What will each party be contributing to the project - money? equipment? expertise? facilities?
The MOU will be a solid working outline for then preparing a definitive, binding agreement - this could be a partnership agreement, a joint venture agreement, an LLC operating agreement, or something of that nature.
A: It's actually illegal for an employer to restrict workers from discussing workplace issues and conditions among themselves, under the National Labor Relations Act.
A: You form a corporation by filing articles of incorporation with the Secretary of State. Then you will need initial board resolutions to authorize various post-incorporation organizational matters, as well as bylaws. You will also need to issue stock to the founders. This is the kind of project I have handled for dozens of clients.