Hello so sorry I missed you when you first requested me.
You asked "What circumstances triggers an audit of the IRA transactions (disqualifying or not) ?"
Just like with individuals
or businesses, there are no specific triggers for audits. The “prohibited transaction” rules
,which, if violated, can result in an IRA being treated as fully distributed to the IRA owner in one lump sum = terrible tax consequences. There are certain situations where the income
earned by their self-directed IRA is not exempt
from current tax (i.e. their IRA must file a tax return
and pay a tax). The documents required by others and sent to the IRS naming the IRA would place the IRA in a position for scrutiny if the IRA did not file the return when needed.
Record keeping was your next concern, Yes you were required (for your own protection to retain the records. The 3 year rule protects but not if the return was never filed and this is for the IRA too if it needed to have ever filed a return.
You could open a second Roth but you need to have a competent tax professional go over the full information for the 1st IRA to determine if there are problems that need to be addressed as well.