Is it acceptable to add additional line items after 811 if there are additional charges that need to be listed? For example: 812. Administration Fee - Payee, 813. Escrow Waiver Fee - Payee, etc.

I am not sure....

According to RESPA (24 CFR 3500)Appendix A, Lines 808–811 are used to list additional items payable in connection with the loan including a CLO Access fee, a mortgage broker fee, fees for real estate property taxes or other real property charges.

Here is a link to the CFR language.

I'm not sure I understand your question - but if your software will print lines to 899 you could have something on all the lines (although if you have that many charges I think I'd be looking elesewhere )- ours will only print through 815 - If we have more then they are lumped on 815 and an addendum is attached that itemizes 815.