For us to get the appraisal from another lender, we have to pay them the fee after they send us the invoice. 

Is is common for the lender to need to see invoices and receipts every step of the way?

After I paid the invoices, he turned around & cancel them & pocket the money.

It is a MassLandlords invoice,NOT a SPOA invoice.

They can pay online or set up auto payment and it will send invoice and reminders as well and much more.

Are all my invoices uploaded to my owner portal?

See below:In two years, never furnished a bank statement showing where security deposit funds were held - no interest paid.Provided a check with a piece of paper with markings for "$75 bathroom door knob" and "$150 kitchen faucet" (No receipts, invoices, etc. - just his handwriting).Check was given on the 28th day of the following month (2 days before due) and has not responded to calls/texts.I sent a demand letter with a reasonable request, asking for the full amount of the deposit because there were no defects when I moved out.

More investors need to get skin in the game besides just the mortgage and invoices.  

After an offer, in due diligence phase, I would request all the details for example, vendor invoices, sales orders, etc.At what point is acceptable to ask the seller for tenant agreements, copies of utility invoices, etc?

Capital expenses and invoice.