I'm 99% the answer is no... but can one learn if they are really in someone's will
Or beneficiary to their IRS?

Can they? Yes with probate or if the will holder is willing to show you. I assume you also mean IRA. Your question begs a WHY?

No. You will probably have to wait like the rest of us.

I have known people that were told, or thought, they had something coming to them from a person, only to find out NOTHING was left to them. So my answer is NO!

Don't worry about it until they die, and whatever the outcome after probate, don't worry about it then either.

Yeh you can. It's up to them to show you/tell you.

You can't be a beneficiary to a will if you've witnessed it though. There is then a conflict of interests. There are exceptions, but the general rule is that if you've witnessed and attested a will, you will not be a beneficiary. Saying that, you would've read the will so it should be obvious.

The only examples I am aware of where a beneficiary can be certain of his/her status is with retirement accounts (pension plan, IRas, 401k's and 403b's) and with accounts held jointly with rights of survivorship. By law one's spouse MUST be the beneficiary of his/her retirement account UNLESS the spouse signs a waiver relinquishing her/his right as a beneficiary. For all other cases - non spousal beneficiaries of retirement plans, beneficiaries of other financial accounts not jointly held, and heirs specified in wills - there is no notice made to beneficiaries prior to the death of the account holder.