In addition to the good suggestions made by Mr. Lounsbery, I would recommend trying to talk to your Public Defender. If you believe in your innocence your recourse is the great American jury trial. Oftentimes you’ll see a different side of your private or public defender when you yourself decide to take the risk of trial. The decision to go to trial and make the DA really consider whether or not they can prove each of the CALCRIM elements of a particular crime is one of the only rights that is available to the defense.
What is your recourse? You can hire a private lawyer that will fight for you. Or you can ask the judge, in a "Marsden" hearing, to assign you a different public defender.
Of course, the other option is to trust the deputy public defender assigned to your case. Penal Code 422 can be charged either as a misdemeanor or a felony. If filed as a felony, it can be a strike.
It sounds like your case might be a misdemeanor because of the offer--PC 415 is typically an offer you see on misdemeanor cases, not felony cases.
Of course, it is impossible to tell you in this forum whether or not the 415 is a good offer or whether or not you should take it. If you would like a second opinion, you can always hire a private lawyer to review your case, look at the evidence, talk to your public defender, and then give you an opinion as to whether or not the 415 is a good offer. My firm regularly handles cases out of Newport Beach.
There may be a few other options available to you other than a plea to a 415. The bottom line is that if you don't trust your current attorney you should find one you do trust otherwise whatever you do, you will have second thoughts down the road. In the end if the D.A. isn't willing to offer anything you are interested in, you must have a lawyer who has the skill and experience to be successful. I would suggest you keep looking to find someone who you have confidence in and will take your case for a reasonable fee.