1. My question is; is Rofo the only one in this community who is able to do that from a technical point of view or do others have the capacities ( codes) to do something like this as well?
There are many people who are capable of doing so as well as many people happy to for a fee. The biggest problem large coins will face in the future is a split community, with half wanting to go one way and half wanting to go another. In that case you might end up seeing coins like BTC-2 or LTC-X11, each with their own network of merchants and supporters who mine or accept it based on personal preferences or market demand.
2. How is the situation regarding algorith change in Btc? How many have the capacity to do a algorith change in Btc?
Same deal here, many people are able to change specifications (the protocol) of coins. The code of coins being worked on is open-source and they are all generally available for viewing on Github. Bitcoin for example:
https://github.com/bitcoin/bitcoin3. Regarding the POS coins. Imagine one of the POS coins becomes very succesfull and expensive. Lets say worth a couple of billion. What will happen when someone changes algorith there eventually by changing the inflation rate up, for instance? I guess this will not be healthy for the price of the coin. Is there a possibilty that competing altcoiners can do such a change to kill a coin?
If PoS coins reach that point I doubt many people will want to or vote to change the specifications and potentially reduce the value of their own holdings. The only 'attacks' competing coins or developers can do is make a copy of the code and release their own coin with different algorithms/specifications. When that happens it is up to them to convince people to use their preferred coin.
4. People in the crypto business are often idealistic, not happy with governments, banks etc. They feel attracted to gold, silver and don't like fiat money that is printed and inflated everyday. These people hate centralization. But what remains of the decentralization ideal, when the algorith of a crypto currency is in the hands of a view?
I feel the centralization argument is slightly skewed, because algorithms and ASICs are being blamed for something that is purely based on money. Centralization exists in BTC and any other coin not because of ASICs or its algorithm, but because someone had the money to buy a large amount of mining equipment. Centralization exists in PoS coins, because someone with money bought majority or large shares at (generally) a very cheap price, now own large amounts of coin, and has the power to double-spend not due to mining power, but because of stake power. Right now any coin is just as centralized as BTC with ASICs can be, because people have spent millions of dollars on GPU farms. The same people will spend millions of dollars on whatever equipment is necessary for whichever coin/algorithm.
The 'cryptocurrency idealist' in me says that if centralization for one coin gets to a point that people are unhappy with it, they will simply turn to a new cryptocurrency, or develop their own, rather than deal with a coin/system they are no longer happy with. What this would do is reduce the value of the centralized coin, weakening the attempts to centralize it due to less money being involved, and help 'de-centralize' it.
5. So, eventually my overall question is; isn't something wrong here? We have a crypto world full of idealistic people, searching for decentralization, trying to get away from overregulating governments, that finally ended in a crypto world that is centralized as well?
I think the kicker is not so much in the value of decentralization, but more in the fact that a pre-determined coin with its 'protocol/rules' can never be truly controlled through 'printing' as much as fiat. I will never be able to 'print' millions of dollars a day extra behind the scenes of NOBL and give it to my buddies, reducing the purchasing power of your own NOBL. The amount is pre-determined, agreed upon by all when they choose to support/mine it, and a coin can be abandoned or 'forked' the second a community member is unhappy with it and feels they can do better.
When the answer to question 5 is, that I am right ( I hope of course I am wrong), then things are not healthy in cryptoland. Then the ultimate solution for NobleCoin would be to become a coin 100% protected against any possible algoritme change. Because every coin vulnerable to an algorith change will eventually be seen as very weak and centralized.
Every coin is vulnerable to any change only so long as people are willing to support it. That is the beauty. If a 'developer' added a change that was extremely unpopular miners/community members can simply mine a 'fork' of that coin. If a majority of miners/community members wanted a particular specification in a cryptocurrency, they can choose which 'fork'/version to support. Sometimes I feel like Satoshi's original idea against 'centralization' was not so much about mining, but more so about 'centralization of power'. I won't deny we have a good amount of power centralized here being the founders and 'representatives', but if anyone would like to fork NOBL and have it accepted on the marketplace also (NOBL-X11, NOBL-PoS, etc. etc.) and support that version themselves, I am more than happy to oblige.
Cryptocurrency lets everyone involved in coins choose which ones to support, choose which ones to accept and spend, and choose which ones have specifications or characteristics that are acceptable to them personally. There is no 'forced' control. Sure there is loss of value if a 'developer' does something stupid or unpopular to a majority, but the 'central bankers' of cryptocurrency can not force you to use a currency that they have 'centralized control' over.