You contradict yourself. First say that the history of a particular bitcoin does not matter, and then admit that this is only true until you use centralized exchanges, otherwise you will have problems freezing funds.
I'm not contradicting myself. Just because there exist services which enforce arbitrary rules, it doesn't mean the coins are the problem. Just as if there would be a merchant in real life, who would not accept your cash because he thinks you're not trustworthy, and asked for further info like bank transactions, passport, phone number etc., it doesn't mean your cash are problematic; the merchant is.
And problems with freezing funds will also arise for someone who buys bitcoins from you that have passed through a mixer on a decentralized exchange, and then wants to bring them to a centralized exchange.
Notice that you repeat the usage of centralized exchange as if it was an indivisible part of the Bitcoin ecosystem. It's not. I have not used a centralized exchange in my life that enforces such nonsense. I trade peer-to-peer using decentralized, trustless exchanges*, just as bitcoin was designed to be.
Conditional freedom is a kind of non-freedom.
Depends on the conditions. If the only condition is "don't use such services", I don't think you have much freedom encroached.
* with this exception.If you don't like the example of centralized exchanges, I can cite a number of others to support the generally self-evident point that bitcoins are not the same.
1. One bitcoin in an address with multiple inputs is not equal to one bitcoin in an address with one input. You can consolidate many inputs into one by making a transaction to your own address, but this will require additional effort, time, and miner fee overhead from you.
2. One bitcoin on a legacy address is not equal to one bitcoin on a segwit address or one bitcoin on a taproot address. You can transform address types by transacting to your own address, but this will also require you to add extra effort, time, and miner fee overhead.
3. There is a number of evidence that investors of a certain class prefer to buy bitcoins not on the exchange, but directly from mining companies, and even pay an additional premium to the market price for owning bitcoins with zero history.
4. Bitcoins from the earliest period of history (about a year after the genesis block) are under close scrutiny by blockchain analyzers, and their transition from a quiescent to an active state can lead to significant consequences. One bitcoin from this period of early history is not equal to one bitcoin from a more modern period of history.
I respect your right to confidentiality, anonymity and privacy, but it seems to me a rather stupid idea to use for this purpose a completely open and transparent bitcoin blockchain, which does not have the native fungibility of coins. I am not against the use of bitcoin mixers, but you should be aware of the possible negative consequences of their use in the present and in the future, which I mentioned above. The spread of bitcoin adoption could lead to the segmentation of the single bitcoin space into partially isolated fragments, some of which may be significantly affected by the efforts of regulators.