James,
Is this typical? Not usually.
That being said, there were a few things that you could have done better. Your have stated some of them, but let me see if I can give you some ideas to fix them.
1) You didn't mention anything about the numbers. First and foremost the deal has to cashflow. At 435k you need to rent each side for 2200 to even think about breaking even, especially in a high property tax state like TX. Don't buy the BS about sub 1% and appreciation. If it don't cashflow don't buy it. Quite frankly if you are having to put out 3 years of profit on 7300, of expenses, the deal sucks.
2) 5k for an electrical panel in a completely renovated 420k Duplex is completely untenable. At that price point, the property should have NOTHING wrong with it. Add to that the missing garbage disposal outlet. That is a good sign of someone who doesn't know how to do a punchlist for renovations. In the future come up with a checklist (read The Checklist Manafesto) and make sure you check EVERYTHING on it. Which leads me to point 3.
If you are investing out of state, and don't have excellent support, cart your butt there and meet them. You did this deal entirely from your chair in CA. You've never been to Austin for any reason. I don't buy the BS that you can invest in a location without ever having been there. So for the price of a plane ticket and 2 to 3 nights hotel, let's say 1500 bucks you risked 110k of your own money on a 440k deal. Save 1500 (10% of your hard earned cash) to lose, what another 7300? Next time slow down, spend the dough to go see the place and establish the relationships to truly make it work.
Finally, stop the pitty party. Stop feeling defeated and taken advantage of. Watch spending money on an attorney. Both the agent and the inspector have no liability no matter what they have said. You signed a document that absolved the inspector of any liability and the broker is not responsible for the condition of the property, only the purchase and sale portion of the deal. Plus, they were probably a sellers agent, with no fiduciary responsibly to you.
Look, I'm not trying to rub salt in your already open wounds. What I am saying is that most of this is preventable. Stop focusing on "I have to invest in Real Estate" and focus on "Is this real estate a good business/ investment decision". Get back to basics.
Stay out of multiple offer situations when you first start, and for good measure stay the heck out of "hot" markets. You got creamed because you got in over your head. 20k over on something that doesn't cashflow properly is an impulse purchase not a level headed business decision.
I would take my next long weekend in Austin, find an excellent inspector (lose the entire group you are dealing with now) and spend 2 to 3 hours going over the house from top to bottom and getting to know the property. Once you know what you are in for, then you can decide if you want to keep it or dump it.
FWIW, I bought a SFR 4 months ago, and just had to put a new AC in. Completely my mistake for not insisting that it be pulled apart and looked at. The roof I know about (2 years max before replacement), but was blindsided by the AC. I won't make that mistake again.
You will do just fine in the future. Everyone effs up a deal. You got yours out of the way sooner than others. Keep plugging along, you'll get it.
Hope that helps.
Good luck,
Jim