What? Everyone being dead means case closed, not that they have to arrest someone for the crimes a bunch of dead people commited. If that were true, then Skyler would be a far better target than Saul, anyways.
They also showed him always taking measures to prevent anything from coming back on him. It made sense at the time when everything was very volatile, but not so much anymore.
None of the people you mentioned would be able to connect him to more than the petty crimes they were involved in, which is no different than at any point of Saul's existence
There was a LOT more than petty crimes that Saul was involved with. He was directly involved with the whole scheme Skyler and Walt did to buy the car wash including the fake toxic water stuff that Bill Burr did, thats state and federal crime there. He laundered millions of dollars for Walt and Jesse and that had to go through legit businesses (like the nail salon, which Saul has to own a few of) and since the source money was meth drug money it all gets tied together with RICO and fruit of the poisoned seed. Now you have state, fed, AND taxes involved. The feds do not need to prove the money was drug money, they just need to say you can't trace the money to a legit source and of course all the owners of those businesses would immediately confess to Saul bringing in bags of cash every week.
Don't forget either the call into Hank that made him think Maria was in the hospital came from Francesca, and she was involved with a ton of shady shit with Saul. If she flips, and of course she fucking will, she has a lot of dirt on Saul. I wouldn't be surprised if we see some of that in this weeks episode, like her taking home evidence or taping stuff.
RICO charges do not require active participation in a criminal conspiracy, only being part of it with knowledge. As Chuck said attorney/client privilege is gone the second the govt proves the lawyer knowingly participated in criminal activities. Nixon's DA spent 2 years in jail just because he knew a little about Watergate and didn't warn authorities, he didn't actively participate. This isn't even going into any of the cartel stuff, the stuff with Lydia, the white power prison gang, just on and on where Saul had light touches but touched in some way or another almost every big criminal enterprise in ABQ. and yeah, all of them died which is great for him, but being literally the only person still alive means he is the biggest target for prosecution now too.
I mean history is full of district attorneys who got fast tracked into politics because they got a headline big deal case that made them famous (our current Vice President), every DA in New Mexico would be salivating at the chance to prosecute Saul Goodman. Its OJ or Johnny Depp levels of trial fame, especially when news casters directly tie Saul to Heisenberg, Walter White, Gus Fring, Los Pollos Hermanos, and the mexican drug cartels. People wildly misunderestimate how much real power the feds have not in prosecuting cases but how they can take away all your money by simply insinuating you can't prove it was legit money. Asset forfeiture is something that would make our founding fathers flip out.
the fake documentary