Hi Lbeach,
I'm also quite a new user of the Cube, and over all it has performed well. Both issues you describe are familiar.
Filament: Just like Dan mentioned, it all depends on the filament. Some work great others don' t. In my experience it also depends on the item you are printing. If there are a lot of retraction actions (the filament is slightly pulled up to bridge a gap) my "bad" filament seems to not get pushed into the extruder (clicking noise) and I get a couple of layers that did not print well. As a result you can throw away the object ;-( I have also purchased an example bag of filament (12 colors) on aliexpress where none of the colors have this issue. So try to find the right filament. (I can mail the resellername, but cannot guarantee it will work with your printer)
WIFI: No solution here, just confirming the same problem (sort of). I have managed to connect the printer to my acces point, and have printed through wifi. But after turning the printer off, the next day I could not connect, I could not even enter the wifi menu. After a reset, I was able to connect again. But now even though the printer seems connected (it has an IP adress), the Cube software cannot connect to it. So it is back to the USB stick.
Best regards,
Chris (The Netherlands)