Does a USB3.0 pen/thumb drive have enough speed to handle editing in Premiere Pro Daniel2 codecs ?
It depends on the USB flash drive, for example some have > 100 MB/s R/W capability and would be similar to working with a traditional HDD. However USB flash drives have chips which are not meant for constant use and lots of writing, and they don't have wear leveling like a good SSD. This means that the flash drive will go bad sooner and you will lose your data when it does.
I recommend using a portable SSD to work with your video projects. For example a Samsung T5 series.