Sewer lines can be inspected by camera. Costs a couple hundred dollars. I've had one house that had a crack that had tree roots in it but otherwise these cast pipes hold up well. I've had more issues with houses built in the 60s and 70s having Orangeburg needing to be completely replaced at about $4500. If the water is on to the property ie not foreclosure, you can easily determine water pressure. If the water is not on there is some risk there. If the supply from the shutoff at street is damaged or clogged your looking at about $1500. You can have water pipes pressurized to check for leaks. From my experience with foreclosures they don't get winterized until after the first winter of the house being abandoned. This means the pipes have already frozen.
When I have water turned on the these old 2 stories I have a process. I make sure there is a good ball valve on the metered side then have the water department turn on water and close the valve. Then I go in with a helper. They stand in the kitchen while I crack the valve in the basement. Then they look at kitchen sealing and watch for rain. Usually the 2nd floor bath is above the kitchen and I have yet to find a foreclosure that doesn't have a burst pipe in the kitchen ceiling. Now this is not an expensive fix once you've located it but there will be plaster that needs cut out and repaired.
The electrical could be an issue. These houses most likely had the plumbing and electrical added after house was built. Sometimes the knob and tube has been replaced and sometimes not. I've only had a couple electrical issues and they've all been minor. Overall I've had good luck with the older houses.
As for cash flow personally my best cash flow is from the older neighborhoods. Wellington Heights and Mound View have the cheapest houses to buy but they have there stigmas. You will have people that won't even look at them based on the location. Mound View you can potentially rent to college students though. I think the next step up would be around Daniels Park, near Penford and over by Harrison Elementary. These houses aren't as dirt cheap but people aren't scared living there either. Also easier to sell to first time home buyers. What I like about these areas is they are in close proximity to large industrial plants with many good paying jobs. Lots of their employees are looking for housing close to work and most of these people work a ton of overtime so they can usually afford the place. I'm sure there are other areas of Cedar Rapids that cash flow well but these are where I've had the most luck.