If they don't want to grant equity or take investment, sure. But doing one of those two things means the legal costs of starting with an LLC (which aren't standardized) substantially outweigh any tax savings, and almost no startups prior to that point have positive cash-flow anyway so taxed profits aren't much of an issue.
Sure, but there isn't an out-of-the-box mechanism to do that. You have to create a way to grant equity, which means you'll need to pay a lawyer—and hourly rates add up quick.
Exactly. Too many people trying to push all starts into a Delaware X corp for their own gain. Not great blanket advice for everyone, do your own research.