Or worse - begin searching for receipts and invoices and cannot find them.If you're recording everything in Excel, and there is not much to record at this stage of your business - then you probably do not need bookkeeping service.

For day to day entries of receipts, invoices, the bank statement, etc. you just need a bookkeeper or you'd do it yourself. 

Normally on this letter you indicate the amount of Deposit you are holding; description of any pre-paid rent for the period; descriptions of deductions including a line item for the pro-rated rent; and if applicable pro-rated utility costs; cleaning or damage repairs per included invoice.

Property manager says he will send an invoice each month - is this how property management works?

Finalize your evidence with proper move OUT documentation, including copy of the notice you received/gave for vacating notice per local law; actual third party estimates for repairs to tenant damage ONLY (or actual invoices of repairs/cleaning completed within the time requirement of the law); and a copy of the tenant ledger showing the past year of charges and payments.

Also, Judges usually do not value YOUR time spent cleaning/repairing...they want to see actual third party estimates or invoices.

This has the potential to go down a rabbit hole where they can ask for invoices for personal loan's utilization and if you alter those documents, you WOULD be committing mortgage fraud

My pet peeve is that is if  I set up invoices for rent I can't just match a downloaded bank deposit to pay that invoice.

HDpro acct, Amazon, etc.. and have my contractors email me invoices.

This will give you experience with managing a small construction project, dealing with contractors and invoicing, etc.