About the deposition, I only know of depositions taken when the insurance company was sued to get the company to release the funds. If that happened, the company rep is deposed, so I guess the bene would be too. Just filing a claim for proceeds is not enough to get him or anyone else deposed. Insurance companies do not depose everyone who ever files a claim.
I think the deposition if there was one could be used against him in court, but I'm not a lawyer so I could be totally wrong. What the insurance company is bound to do in a court of law at the time of a lawsuit and what LE suspects is in no way connected. The insurance company doesn't have any control over whether or not LE considers someone a suspect. The point is, the insurance company is not going to be pressured to pay that kind of money to someone they aren't sure didn't have anything to do with the murder. You can't profit from someone's murder like that, period.
The ins. co. can be suspicious all they want, but if the person is officially no longer a suspect or was tried and acquited, there is really nothing they can do. They can't just pay because they don't like someone or heard a rumor about them.
That job is why I can tell you that it doesn't matter how great someone's parents are or how great someone was raised, you can just never be sure that someone isn't capable of murder. I'm sure Mark Hacking, Scott Peterson, Justin Barber, Ted Bundy, Steve Grant (and so on) all have family and friends that think they were raised just fine, and yet they were all convicted of horrible murders, mostly of their spouses (except Ted Bundy). All of them had friends and family who said they could never do such a thing-but they did.