I live in Los Angeles,  which is obviously a super competitive market with high barriers to entry.  

Lots of competition!

I would like to have a solid mortgage broker in order to get potential buyers pre-approved at a competitive rate.

The MLS and auction properties have too much competition and amateur investors are willing to pay too much for them.

Competition!

The realtor is saying they are willing to come down quiet a bit, but I have little experience making offers  so I'm not sure what percentage is "quiet a bit"..The good thing is: not many people want to buy two houses so the competition is scarce.

With a culture built on hard work, economic progress, and family, Birmingham is a proud American city.General Facts Named “Magic City” due to its fast population growth during the height of the nation’s manufacturing age48th in population among the nation’s top 300 metropolitan areas (City of Birmingham Website)Largest city in the state of AlabamaConsistently rated as one of America’s best places to work and earn a living based on the area’s competitive salary rates and relatively low living expenses (Under30ceo.com)Jefferson County IB School is in top 25 “America’s Best High Schools” (Newsweek 2011)One of the largest banking centers in the U.S (Wikipedia)The city is investing over $1 billion to revitalize the downtown area into a 24-hour mixed-use entertainment district (Downtownbatonrouge.org)The city is home to “the Oscars of dining” winner from James Beard Foundation (Birmingham Visitor’s Center)

Review the comparables of recently sold properties along with active & pending properties;  i.e. your competition.  

In this case, do people typically list the ad with the base rent (so that it's competitive with other similar sized units in the market) and put the full rent amount with utilities included in the ad description?

Also refresh your calendar often.If you have instant bookings enabled it will also help.Search your area on VRBO and see what the competition looks like.