More channels do not help the hearing aid sound more natural. Nothing helps the hearing aid sound more natural except turning it off or wearing it more. Remember, what YOU think of as natural reflects a 50-70 dB hearing loss. That is NOT natural. If you want it to sound the same way you heard before, then you’re not going to hear any better than before.
For the Squeakychu… The tinniness is WHAT makes the clarity better. It is a result of amplifying high frequencies. It will become less bothersome the longer you wear your devices. The feedback squeaks that you are getting are a result of the fitting being too open. You need to occlude your ear more by reducing the vent size or using a more closed dome. You will feel slightly more plugged up for a while, but that too will pass and then you will be happier.
As for understanding soft voices, there is a setting in Widex’ fitting software where soft speech can be turned up to maximum audibility. That should help.
You should post your audiogram and word recognition score and I can maybe give more insight.