Welcome @Chris Marsh. I work with more buy/hold investors from California than anywhere else in the world. There is some really good advice here from both @Andy Rumple and @James Wise. Here's my take on working with OoS Investors.
#1. Location - There are several good cash flow markets in the US and Indianapolis is one of the better ones. Picking your markets are half the battle. Understanding those markets are important too. I agree with Andy, the 1% rule is the absolute worst deal worth considering in Indianapolis. I roughly figure my max "all-in" price at 85 X 1 gross months potential rent for financed deals. My cash deals have to be closer to 60 X (similar to the old 2% rule) but they are harder to find and usually an asset class that doesn't interest me. I hate when my contractors get intimidated at gunpoint during a rehab. This just happened at a Haughville rehab I'm coordinating for an OoS investor. I am not a fan of investing in that neighborhood, but the buyer that the numbers looked good. It makes me wonder what kind of tenants we will be dealing with though.
#2. Strategy - Personally, I'm a bigger fan of leveraged B Class investing. BRRRR is ok, but there are complications that are never really explored publically here. Most BRRRR deals are only netting about $500-$1,000/year, because everyone is refinancing all of their money out or more and the debt service kills their cash flow. That's fine, but somewhere... someone got an idea that they can BRRRR properties and cash flow $200+/mo on every deal and that's not usually the case. Other limitations to BRRRR are seasoning time, LTV limits, appraisal problems, etc. There really are a ton of strategies and some fit your resources and plans better than others. Talk to your PM and Broker to see where they are seeing success with their other investors.
#3. Team - It sounds like you've already got your nucleus established. This is huge. Investment outfits generally only give you one perspective. Building a team from different companies/offices will give you better perspectives and you are much less likely to get taken advantage of. In Indianapolis, we've had a couple of predatory turn-key outfits that have caused problems in the entire market. This is eliminated when different team members have different motivations (i.e. general contractor, realtor, inspector, property manager, insurance agent, lender, etc.) and give you their opinion on the deal.
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To address your specific struggles.
1. Turn-key homes are ok to start with, build a foundation for your portfolio, and get introduced to a market. You will have no equity and lower ROI. Many turn-key PM's are barebones as the money maker for the outfit is selling turn-key homes. Property Management is a much harder job and much less profitable. The turn-key company stands to make $5,000-$15,000 profit selling you the home with no long-term overhead. The PM stands to make $1,000/year and run a company and several employees out of that money. Where would your focus go when growing your company?
2. There are a lot of things to consider about rentability.
Location is foremost importance. Know your tenant demographic. In indianapolis, I don't recommend larger, family style homes in Center township. Crime is higher. Schools suck. There are some great neighborhoods, but I prefer Bungalows or smaller 3 bedroom homes in Center township. When in the exterior 8 townships, I prefer 3 bedroom+ homes with 1.5+ bathrooms at over 1,000 sq ft. This is to attract families who will be using the home for years while their children are going through their education.
Pricing. Homes don't rent for 1 of 3 reasons. Over-priced. Poor condition. Poor marketing/response from leasing team. Know your markets price point and find out what the finish/trim of rentals in that price point looks like. I am currently working with a prospect who is looking to purchase a duplex in South Broad Ripple. It is currently rented for under $600/mo but could rent as high as $1,200/mo with the right renovations. We have already research pictures of the $1,200/mo rentals in the market and determined what it will take to increase the rents to that range. If your priced right and in a desirable location, there shouldn't be any problems.
Your PM's ability lease a home. I hear someone every week tell my that our leasing team is the only one that answered the phone or called. If they don't answer the phone, schedule tours, or pursue prospects to apply... it will not rent. How about pictures and listing descriptions. There can be a huge disparity of quality and if a property doesn't capture and/or enhance the best features of the house, it won't create the necessary interest to draw in a prospective tenant.
3. Your last point is interesting. The 60 day listings may be the only ones that haven't rented. We see rentals that lease in 3 or 4 days all of the time. You may not find them on Zillow because they are on and off so quickly. You may just be seeing the ones that have problems, like price, condition, leasing team responsiveness. I worry less about specific neighborhoods as I do school systems and crime. Neighborhoods may occasionally draw a higher caliber renter, but there is usually something specific to that neighborhood (low maintenance living, community amenities, secured community, etc.) and it should show up in the rent ranges. A good and active PM should know many of these nuances more than anyone else. Unfortunately, the best data for Days on Market, etc is pulled from the MLS and many homes in Indianapolis are not listed on the MLS anymore. It's more expensive and they rent just fine with Zillow and Rentals.com. The problem is that there is less data from these sources. I'm more interested in retail sales volume. If homes are selling to owner occupants, people want to live there. Desirability drives appreciation of both the sales and retail market. If I'm considering a property, I look for a minimum of 10 "retail" sales in the last 6 months in a .25-.5 mile radius. These will be fully renovated homes sold at the top of the local market rate. If there are homes like that in your area, you should be just fine.
At the end of the day... you don't need every deal to be a homerun... just set reasonable criteria, and pull the trigger when you meet that criteria. Ensure that your numbers are similar from a variety of sources and use the most conservative numbers you get.