I think there's some improvements here, but it seems like you're focusing on

1. Spam transactions

Sure, they can be bad. If they are phishing. But most users don't mind getting airdropped tokens they don't pay ram for.. REX was a problem, but the original resource model was the real problem. Why would 1% of tokens = 1% of resources? Why not charge for the the resources actually used per block, and make a percentage of available resources be available to a percentage of the people actually using the resources?
The truth is, SPAM makes blockchains look good, as it flexes the TPS and the TX per day. No interested stake holder goes back and checks the actual TX log before investing or as a part of their onboarding experience. Try focusing on what you WANT TO HAPPEN, not false evidence appearing real.

2. Preventing RAM hoarding

Again, this isn't a real issue. Speculation on any market is to be encouraged, or at least understood and molded into a beneficial practice.

There's another approach where you allow a user to allocate any amount of RAM to be reserved for them, and then automatically sell that ram (or 50%) if the price goes up 2x. This is perhaps not a good idea, but FOCUS ON THE SOLUTION, what you WANT TO HAPPEN. What we want to happen is affordable RAM prices. Deeper, what we want to happen is people have the RAM to do what they need to do. Focus on that. I can provide suggestions.

Also, ask for some help.

You are destroying all your systemic designs by focusing on small negatives instead of further developing the goodness.

Charging TX fees is about the biggest step back I can imagine. The little gas tank is better that wasting time and money with Power Up, but it's a huge step away from the right direction.

You find the right direction by figuring out what's working and accentuating it.

Please ask for community help. I'm not the only one jumping up and down waving my arms trying to help you. You aren't the best. I'm not the best. Together we are the best, only if we recognize and HONOR eachother's value and ideas.

@douglasjames