Uh, the way I understand what you say: the bitcoin price, is the price of 1 BTC in $$, right ?  Commensurate, is proportional, right ?
Let us say that the proportionality is 0.0001.  Then that means that a fee is 0.0001 BTC, no ?  So if BTC = $1000,-, a fee is $0.10, if BTC is $1000 000,- then the fee, with the same proportionality, is $100,- , no ?

Yes, you are correct.

Or do you mean "transaction amount" instead of "bitcoin price" ?

But then the miners will only take those transactions with highest absolute fee, so only the very large transactions.  Because for them, at a certain point, including an extra transaction (and risking the loss of the entire block) will not be beneficial any more below a certain absolute fee.

That would mean miners only care about transactions that involve buying mansions, yachts, private jets, etc. No, as long as the fee is proportional to the price of bitcoin, it doesn't matter if they accept transactions for buying a private jet or a transaction for buying an apple. In a block to be mined, the total fee will be a fixed % of the total transactions in that block. So a miner does not need to have bias on which block to mine. A block may have just 10 transactions involving purchases of a private jet each. Another block may have 1000 transactions involving purchases of a bike each. Something like that. But from both blocks, miners will earn similar fee and will have no bias on which block to mine. There will not be a block that reward $100,000 worth of fee and another block that reward just $0.1 fee just because the first block involves a transaction to buy a private jet while the second one involve transaction to buy an apple. Mining each block in totality will gain similar fee regardless of the value and type of transactions in each block. However I am not in a position to clarify how the details should work out. Ask yourself WHY would the miners want to push the non-whales out of the blockchain? Who will be left paying the fee to the miners once the non-whales are totally out? The fee, just like interest, is not important to the miner (bankers) when the time comes for them to dominate mining 100%. The bankers don't care about the interest because they print them for free anyway. Yes, mining is costly now but it may not be so later when they finally decide those PoS vs PoW thing after centralizing 100% of mining power. Then the fee will not be an issue.

Bitcoin was a unique possibility for a few initial players to become immensely rich ; and they had the right timing: after a financial crisis, it was easy to get a big crowd of enthusiastic believers on their hands.  These financed the initial gains of a few whales, who then, had enough means to promote it more.  Such an opportunity happens only once.  There is no need for "dark forces" behind it: in fact, the failure of bitcoin to get seriously adopted indicates rather the fact that there are NOT very powerful dark forces behind it.  Bitcoin was just a hype with right timing, some distrust in banking, and unrealistic promises (that can't be accomplished with its technology, but which need sufficient technological insight and lack of starry eyes), sufficiently enthusiastic useful idiots and so on.  Overstock was a family affair: the big boss of overstock was talked into bitcoin by his own son.  Microsoft was on the look to hook onto any hype that could pull it out of its morass.  

Ask yourself this. If you were back in 2009/2010 and you happened to mine 100,000 units of bitcoin (worth $120,000,000 today), will you travel around the world giving talks about how wonderful is bitcoin? Bear in mind back in 2009/2010, 100,000 bitcoins may be worth just $10. That is simply not how the sheeps (that is us) in general, works. That is why you hear of cases where people have loads of bitcoins but they tosses their computer to the junkyard because the bitcoins that they have in boatloads of 'em was close to worthless. They only find it a treasure now after the price adjusted upward thanks to Mt. Gox. Humans in general are not the same as those from the shadow elite group. Humans in general are sheeps, followers, impartial, and inactive. The shadow elites are trained and groomed to think big and do big and directs the focus of the world in to big projects. Will you fly around the world to give free speeches if you have 100,000 of bitcoins worth $120 mil today but worth just $10 back then?
 Did you really see it coming? You think everything is coincidence? You think the shadow elites are in power because they think it was just a coincidence for them to be in power? And most dumb thing is, you think some genuine whales would be interested in an almost worthless, useless and unproven digital tokens back in 2009/2010? You know back in 2009/2010, we didn't have as much bullish news of bitcoin developement that we have today. We didn't hear news of so and so corporation adopting bitcoin, we didn't hear news of countries legalizing bitcoin, we didn't hear of news of merchants accepting bitcoins. In that time, bitcoin was almost truly worthless, useless, and unproven. You think a whale wanna take a bet on that?
 I wouldn't even want to waste $1,000 even if I was a whale back then.

If there were powerful dark forces behind bitcoin, they would have twisted Amazon's hand to accept bitcoin: the story would have been entirely different.  Bitcoin, as a payment system, is essentially a failure.  However, as a greater-fool game, it works marvellously, for the time being, like all greater-fool games, that promise quick riches (and yes, there are a few hundred of quick riches in bitcoin, living off all the donations by the "adoption" crowd).

Things are working out smoothly, not abruptly.

You are underestimating the explosive combination of useful idiots believing in some libertarian dream, combined with the power of greed and the illusions of quick rich.  THAT is the power behind bitcoin.  Not "organized dark forces", but an explosive mix of foolish idealism and greed.  It is what keeps it up, and this is more powerful than any cigar-smoking "elite" making evil plans that never work out as expected.  Greed and naive idealism.  What more do you need ? What is better than naive people thinking that their idealistic nonsense is going to make them immensely rich, combined with some smart money that sees the opportunity to exploit this enthusiastic propaganda for making a lot of bucks from starry-eyed greedy idealists "adopting" their new toy ?

What evil elite plans that you even know of, never mind if you know they never work out? If you think a bunch of idiots/sheeps can be so organized and effective that they can make bitcoin to where it is today within 8 years, you are way overestimating the idiots/sheeps. You may believe what you choose to believe. You may believe the idiots/sheeps are transforming into some advanced beings that finally have the tools and power to topple all governments and bankers in the world, that the governments and bankers are just helpless to do anything but tag along like a dog. You may think that way... Anything that makes you feel good, dude.