Obstruction of justice is a felony. It’s a big deal. Obstruction and lying was what was going to get Nixon impeached before he resigned weeks before the hearing.
And trust me, when you’re the subject of the investigation, no one gives two shits “what you can stand.” The Feds will go after you with everything they have, and their resources are almost limitless. Manafort and Flynn are already whining about running out of money due to legal costs.
And if you don’t think Mueller won’t find anything, please. This is the guy who put John Gotti away as an assistant AG, investigated and prosecuted Enron executives, was the Director if the FBI, and a Marine Grunt with a Ranger tab in Vietnam. He knows what he’s doing and he recruited some of the best talent in the legal world. Trump can’t even hire competent counsel, and when he does, they quit.