About #1, if you don't believe me, try sending out a transaction on a Sunday. I've had transactions be confirmed within the hour at only 40 sat/b which comes out to around $0.20 worth of transaction fees in contrast to sometime like today when the fee is around 300 sat/b. It all depends on the mempool load, which happens to be lower during weekends. That being said, I still think a scaling solution is a must for Bitcoin, but that's outside the scope of this thread.
You have your reason for saying that because sometimes too I have made some transactions as well while some confirms faster than the other but I just couldn't linked if its related to less traffic on the network during weekend but I guess I will have to try this as well. I feel there is need for the issue of fees to be sorted so people will be more encourage to use more of chip mixer service.
Fees are quite low currently if your wallet lets you set a custom fee. As you can see
here, even transactions with fees of <50 satoshi/byte are expected to confirm in about six hours, which is fine if you're sending overnight or online with low priority (e.g. to a friend).
I used chipmixer a few days ago and I got tricked, after sending my coins I got 3 small chips with the promise of merging them to get a big chip but the merging button wasn't working then I had to pay fees 3 times with one time of my main deposit, literally I lost 20% of my coins just paying fees. lol
Chipmixer does not have fees - you pay what you want to. You should
contact support.