With greater yield comes greater tenant management issues. A passive income experience it would not likely be.
That depends on the property, the suburb and sometimes just luck. I saw a post somewhere from a guy who'd bought in SA, the tenant hadn't paid rent, trashed the place and then left. The agent said to him basically tough, 'I can't be bothered to manage properties in this area anymore', and he was left to deal with it on his own and trying to find a new agent. Not sure how it worked out for him but not pretty after all the purchase costs and holding. I wouldn't view that purchase as an asset but then who knows over time? Lots of people are doing well in similar suburbs. He'll maybe do just as well in the long term as someone who paid huge BA fees, big stamp duty etc etc on a property somewhere more popular with investors and relative risk of oversupply, reduced demand, stagnant values/rents etc.
High yield is definitely important but you obviously have to know the level of risk and discomfort you're happy with. Personally I don't want to hear about 'oh well, the tenant doesn't pay all their rent but the house is near a cbd so might be worth a fortune in 20 years'. That's just MHO. I think payment now is important because there may be no future gain. If it's high yield I would want the tenant actually paying agreed rent, or you're fooling yourself.
I can say from experience that paying down loans does take forever. We tried increasing our income from employment and are doing well but it still takes years. Our biggest investment gains have been from properties nowhere near a cbd, with no research (just luck as we happened to be living nearby and saw what was happening), no BA's, thousands spent on LMI, stamp etc. It's a gamble though so why not if you can afford it.