@Art Maydan
1. You can absolutely do that, some people prefer not to do the work themselves and TK is a much better fit for them (less headache). If you are a TK provider, you want properties that are in great shape since they will be easier to maintain (think about if you were a property manager, and you make 10% of gross rents regardless of the type of property, do you want to manage properties in top shape or properties that constantly need something fixed).
2. Some TK providers have termination provisions/limitations in them (early term fees, or make you prepay the 1st year of management fees), but that is definitely something that you can do.
$50K homes with a 15% cap rate can quickly turn into a 0 cap rate if 3 months in you need a new roof, HVAC, etc. If you can find homes in good shape that need minimal repair and good property management (that screens tenants well), then you're all set and no need to work with a TK.