In general those Rexton aids are fine. Not my favorite, not my least favorite. They should be pretty comparable to Resound aids from Costco. However, dying after only 8 hours means there is something wrong. Do not keep your current pair! Make sure you get a brand new set.
Your other issues should be easily resolved if your HIS knows their stuff.
2. Always shut the aids off if they aren’t in your ears. The charger should act as a low grade dehumidifier. If you need a to use a separate hearing aid dryer, then you should not be using rechargeable. The recharging process takes many hours, so does the drying process. You don’t want to set an alarm in the middle of the night to swap between charging and drying.
5. Use whatever color you like. I personally wear black and silver because I like the high tech look.
6. Should be very easily resolved. A good HIS should have made sure you could hear them before you left on the first day
7. Setting up additional programs is very easy. I usually don’t recommend many programs, but why not have a couple options? Keep an automatic program and a manual program.
You also mentioned some hissing. That is not normal. Perhaps a new paper of aids will solve that issue. Often, however, it’s just a matter of proper programming.
If I were in your shoes, I would shop around for a different hearing provider. Your current HIS doesn’t seem to understand some of the most basic functions of your hearing aids.