Average agent commissions in the Los Angeles area

[Kelly M.]

I am looking to sell 2 properties right now - both located in Northern Los Angeles (specifically Thousand Oaks).  I am most likely going have friend of mine as my listing agent to sell both homes.  

I have 2 questions:

1. What is the average commission rate to be split amongst agents in the Los Angeles area at the moment?  What are the consequences of offering less than the average amount and is it "rude" to do so?

2. Because I am offering a single agent the opportunity to sell 2 properties simultaneously (one should go for about $600K and the other for about $750K) - is it fair to negotiate a lower commission rate with my listing agent?

I clearly don't wish to be a cheapo jerk but I want the best outcome for myself.  Is it kosher to negotiate these things, if so, what are some guidelines so as to not put people off?