For example: If you need the grass cut or a door knob replaced on your IRA property, you are supposed to hire someone to do it, send the invoice to the custodian for payment, which they charge a fee each time. 

and is there any invoice from the actual tradesperson if it comes from the property manager?

*IF* he has other clients he serves, then he can be an independent contractor and you could elect to pay by invoice, and that allows you to use 1099-MISC.If you directly 'employ' this person, then you should withholding SSI and paying W.C.IMO, I've always attempted to avoid employees due to the extra tax accounting and liabilities, and much prefer to use 1099 contractors.

Are all my invoices uploaded to my owner portal?

I use a custom invoice to for monthly rents, a better way than the simpler way of just crediting rents to a sales account, and debiting cash through a journal entry or deposit screen.

Ask for copies of any permits and invoices for the 'new' work mentioned.

We set up quickbooks to create invoices for tenants.

I certainly recommend using the invoicing feature of QuickBooks for multiple reasons (cashflow, past due rent tracking etc...) and if you have QB Online hooked up to your bank accounts, it comes in as a match.  

We are able to contact several vendors at once that have quality community reviews, and our software makes this step much easier than spending hours searching through references and individual sites.If you guys had a service like that available to you to you on the landlord/investor level I'm curious as to what you would want out of a service like that, and how much you personally believe you would pay for a service which finds reliable vendors, schedules them, and gets the invoices with ratings for you?

Invoices for recent capital expenditures?