In Conshohocken the ratio is skewed by the large apartment complexes that are rental-only. If you exclude them, it's probably 30% rent vs. 70% own. Also, statistics for Conshy usually include all of 19428 zip code which includes parts of Plymouth Township. Lastly, the % of the population that rents is high, but the % of houses that are rented out is much lower than owner occupied. Meaning 4 tenants will pile into a house, but next door is a home owned and occupied by just one person. In that scenario 80% of the population would be renters (4/5 people), but 50% of the housing stock are rentals (1/2). Make sense?
As for cash flow, the newer/high-end construction homes won't cash flow, the older housing stock is much more feasible, but expect a meaningful amount of renovation. I think house-hacking would work great here, as there is a steady in-flux of jobs and increasing incomes. For cash-flow I would wait until a down-turn in the market. Neighboring towns such as Bridgeport, Manayunk, or maybe Ambler would cash-flow better. Norristown always looks great on paper, but can be a bigger headache as a landlord.
