Passive to me is management in place on every one of your properties so you can sit on a beach and not get a single phone call, unless of course your house burned down.
10k a month after tax? I want to be rich one day, rich with "F U" money, but I would be happy just to replace my salary at this point and I get a little less than half of that after tax, which is great mind you. Just coming into an office everyday isn't always the most enticing thing lol.
I think that's a long term goal, unless you hustle, save every penny, find the best deals, and put in 100 hours of work every week for those next 7 years.
I do have one polish friend, who hasn't stopped working 100 hour weeks for the past 3 years and at 28 he is probably almost at that goal, and he said it's been miserable. He's about to take a 2-3 month vacation then start up again. No life outside of doing the BRRRR strategy really, even meeting girls, family anything. He has just been so miserable lately, but it will pay off down the road.
If you are willing to do that, and educate yourself about all the terminology, all the tax implication, legal aspect. He reads books when he has a moment, listens to audio tapes when driving, and that's his life. Drives a beat up 2000 corolla that looks like a homeless person sleeps in.
Great thing about today in this country is anyone can be rich if they truly want it.
PS, cashflow is king. Don't try to pay down your houses quicker, just leverage and build up doors like you said.
Good luck man!