Let's say I deposited 0.02347273 BTC to ChipMixer on January 1, 2021.
Its a real long intervall not really neccessary or ?
Not really, but you asked for this:
On an anonymity sight
For anonymity, it's great to have an old vouchers at your disposal. He's a real life example:
due to my intent to expose the blockchain data from this transaction, I decided to use an address from ChipMixer. The address was obtained using ChipMixer voucher codes that I set aside for this potential purpose in November. I always keep a moderate amount of money in Chip vouchers, just in case I need to do something bad for my privacy. The money for these vouchers may have been deposited by me anytime in about the past three or four years; thus, any blockchain observer who identifies Chip inputs will not find it feasible to guess which were mine.
I make sure to spend the full amount, without creating a change address.
Is this only possible to spend the entire funds from the wallet, or are there any other duck-tape fix-all for this except the option "do not mix" in scenario 2 .
It depends: if you're not careful, "change" always has the risk of linking it to some of your other addresses later on. But small change also leeds to extra transaction fees, and if fees go up, it might not be worth sending at that point.
I prefer to get rid of change, one way is using an instant exchanger (on Tor, of course) to convert it to Bitcoin Lightning Network, or Monero, or plan your payments such that you can pay for multiple services at once.
Should i use "Use multiple change Addresses" option in electrum if i use scenario 2. ?
I don't think that helps: multiple change addresses can hide which address is your destination address, but it gives more and smaller inputs and thus higher transaction fees later on.