The fault in your assumption is 1. that this would discourage corporations from buying up;
Did you plug in some numbers to see how much you pay when you own multiple homes? Rental units are not profitable when people can buy a house for cheaper than your property taxes on the same property. And normal people can do hostile buyouts from corporate landords too.
Land is a natural resource, and like air or sunlight, nobody deserves to own it more than anybody else.
"But my family has live here for generations!" sounds awful similar to "I deserve it because my great great grandfather killed the people that used to live here."
You get to decide how much the land is worth to you. If you value it honestly and somebody else values it higher, a trade benefits both of you.
So rent is several times more expensive than a mortgage on the same property. Now what?
What does someone deserve to own? The value created by your own work yes, but nobody deserves to own natural resources like land more than anybody else. The whole point is that you get to decide how much the property is worth to you. If it's worth more to someone else, you're both better off for the trade. The only losers here are people trying to cheat on their taxes by giving a "low" appraisal, and people trying to hoard multiple properties.
Plug some numbers into that formula. If you own a $100k property, you pay 1k in taxes/year If you own 10 of those properties, you pay 100k/year. This would mean you have to charge more in rent than a mortgage would cost to buy the same property. The business model would become unprofitable.
Think about what the investment company's tax rate would look like. They'd be bankrupt instantly. They'd have to pay 10M/year in taxes to maintain ownership of $10M in property.
Eh, probably paid like 25k for a house that's worth 500k now or something. Really what we need to do is make property taxes scale more aggressively, so it isn't economical to hoard more resources than you can actually use. Maybe something like annual tax owed = (value of all real estate owned by one person)^2/10,000,000. Perhaps with a grace period for new construction/renovations.
As for appraisal, let people declare what their property is worth, and force them to sell if someone offers 20% more than their claimed value.
I caught a (wild) rabbit with a bucket.
It was running from a dog and fell into a window well. It got so panicked when I climbed down it almost made it out on it's own (it was about 8 feet deep). So I set the opening of the bucket against the wall with a small gap, to give it somewhere to hide, then went to the other end of the window well, and it crawled right in when I approached again. Covered it with a towel and lifted it right on out.
I've only bought a couple early access games, but in both cases I played the demo long enough to justify the purchase price.
After a couple thousand hours in KSP1, I still managed to dodge that bullet. The only new feature I really cared about was multiplayer, and I knew it wasn't going to happen when they they started early access without it.
Maybe entering the portal takes as much energy as it would take to climb the long way? If the other end is on the moon you have to enter at 10km/s or something else you fall right back out. Warning: I am not responsible for damage caused by extreme tidal forces.
Why? You can force them to sell you a property and pay less on the mortgage than they pay on the same property on taxes.