What does 0.1 btc minimum mean? Does it mean I must have a minimum of 0.1BTC to participate in a coinjoin tx?
This means that the input you are using to participate in the coinjoin features has to be more than 0.1 BTC.
So, owning more than 0.1 BTC is not enough, you need to use/spend more than 0.1 BTC in such a transaction.