LedgerJournalEngine and LedgerJournalCheckPost

I am creating and posting Dynamics AX Ledger Journals from C#.

I want to use the two helper classes the come with AX,

LedgerJournalEngine and LedgerJournalCheckPost, to validate the journals I create.

My questions are:

1.) How do you get a list of errors -> voucher from either of these classes or some other class?

2.) Can you simulate a post inside of a AX transaction and roll it back?

2-a.) If you roll back a posting in a transaction will AX be smart enough to reuse the voucher numbers that got rolled back?

I ended up with:

public static ERSImport_Errors PostJournal(int64 _journalRecID)
{
    LedgerJournalTable          ledgerJournaltable;
    LedgerJournalCheckPost      ledgerJournalCheckPost;
    LedgerJournalID             errorJournalID;
    LedgerJournalEngine         lje;
    ERSImport_Errors             errors;

    boolean                     ret = true;//True we posted this journalRecID
    LedgerJournalTrans          ledgerJournalTrans;
    ;

    errors = new ERSImport_Errors();
    select crosscompany ledgerjournaltable where ledgerjournaltable.RecId == _journalRecID;

    if(ledgerJournalTable == null)
        throw error("Could not find ledger journal table provided");

    changecompany(ledgerJournalTable.dataAreaId)
    {
        ledgerJournalCheckPost = LedgerJournalCheckPost::newLedgerJournalTable(ledgerJournalTable,NoYes::Yes,NoYes::No);
        lje = LedgerJournalEngine::construct(ledgerJournalTable.JournalType);
        lje.newJournalActive(ledgerJournalTable,true);
        ledgerJournalCheckPost.parmLedgerJournalEngine(lje);
        try
        {
            ledgerJournalCheckPost.run();
        }
        catch
        {
            while select ledgerJournalTrans where ledgerJournalTrans.JournalNum == ledgerJournalTable.JournalNum
            {
                if(lje.errorExists(ledgerJournalTrans.Voucher))
                {
                    errors.addError(lje.errorLog(ledgerJournalTrans.Voucher),ledgerJournalTrans.RecId);
                }
            }
        }
    }
    return errors;
}