Whoever from Intuit told you that there aren't free trials (e.g., of Windows) was incorrect. You can download pretty much any product from here: <a href="http://support.quickbooks.intuit.com/support/ProductUpdates.aspx" rel="nofollow" target="_blank">http://support.quickbooks.intuit.com/support/ProductUpdates.aspx</a> (click the "Choose a Different Product" link) for a free trial. Ideally, one would use the same version on Windows as on Mac for the conversion process... so to convert a Windows file to Mac 2014, you want to download Quickbooks (Pro) 2014 for Windows, open your old Windows file there to upgrade it to 2014 format, then File > Utility to export it as a Mac 2014 format.
I know nothing about Simple Start, so someone else would have to help you there. I never understood why the product existed... and I guess Intuit questioned it as well, since it was dropped after the 2010 version apparently.
It does seem that your original transaction recording in Simple Start is likely the problem. A 'name' in QB can only be one thing - Vendor, Customer, Employee/Other... - and so by using your customer name as the Payee for your Bills in SS instead of the Vendor name (with the Customer as a memo perhaps since SS apparently didn't support Customer:Jobs) - things sound like they got very confused. If you need that historical data, you would have to change every transaction to make your records per vendor and per customer correct. Otherwise, you might want to save one copy of your file for historical purposes (with these errors/billables) ... and save a new working copy that you clean up by deleting all of the historical data and cleaning up your Names. Or start completely fresh. (??)