You call yourself thetaxdoctor1 but you don't seem well versed in the concept of equity and debt basis.  Are you sure you should be preparing these type of tax returns? Maybe some continuing education classes first?

And why review 10 years of returns when the statute of limitation has ended on the majority of them?  Finally, reveiwing returns only shows what was reported.  Without the supporting documentation you have no clue whether the returns are accurate or not.