As an agent I always tell this to my investor clients who are looking to sell:If it is a single family home - you are better off selling it vacant with fresh paintIf it is a duplex/triplex/quad - leaving one unit vacant and "rent-ready" can be beneficial. 

To manage tenants effectively, I'll enlist the services of a reputable property manager.

I am on a bunch of wholesaler's lists and after analyzing hundreds of deals for myself and my clients I found one that was from a reputable licensed agent/wholesaler and I pulled the trigger.

Calling  all investors and agents lets connect and get some work done ! 

A deposit is normal, but remember it can and should be structured like a deal on the MLS with an agent. 

Trying to find a reputable website to find properties that have tax liens on them?

Are the landlords still expected to pay commission to agents on both sides, leasing and showing ?

We have almost always just dealt with the listing agent (LA) on deals we have done (40+) or deal directly with the seller.

I want to find agents and lenders for properties in the San Diego area.

It's very easy to get into a situation where the lender, property manager, and the insurance agent are all profiting more than you.