When buying at auction, do subsequent grant deeds get wiped out? Do we have to worry about them?

1st trust deed is up for trustee’s sale. What happens to all those subsequent grant deeds that the original buyer on the grant deed recorded on same date as the 1st trust deed, keep changing (recording) from their name to another person’s name — (ie. John Doe as married man hereby grants to Mary Doe and Jane Doe, joint tenant? Do those get all wiped out as well like junior loans?

Yes, they would be wiped out. With few exceptions (like IRS liens), the trustees deed resets title to the time the deed of trust that was foreclosed was first recorded.