The temptation to pass on bogus costs and skim is great and limited partner most always has bad results.Such as: cash calls, lawsuits, errors, hiring family and they are vastly overpaid, tax audits to name a few. 

Self-certifications are subject to an audit by the city.

You can also deduct mileage, but you are supposed to keep contemporaneous logs; if you're audited you must be able to provide these. 

For the DD aspect, your local PM can usually help by doing lease audits, and physical DD. 

I would take full responsibility for any audits, etc, since I'd be preparing the taxes.

A 1099 is how the IRS catches people who don't pay taxes, so it could create an audit flax.

If you get audited it will be up to the IRS to decide what is "Reasonable" 

But you must have a pre existing relationship with them. 506b also has onerous reporting requirements like a yearly financial audit that will run you $10-$20k, so if it’s less than $1M a 506b may not be way to goAnother is a reg a+ offering but that costs $100k+ to setup and requires registering and review by sec.If you want passive investors who are not accredited there are not many options.

Can I still deduct those or is that not recommended incase I get audited. 

Anchors and national tenants will often have a form estoppel that is an exhibit to their lease.In residential, a lease audit is typically performed versus estoppels.