If you are doing E6 exclusively, then all washing is done on the processor. I could be wrong here as I haven't done E6 for close to 6 years.
Anyway you will not need the Cascade washer. If you ever do decide to process by hand the cascade washer is one of the best hose systems that plugs into the top of the tank and allows flowing water which has been designed to allow air to enter the water system and create turbulence, thereby reducing water consumption.
The film cassette opener is overkill, I and a lot of others just use a bottle opener.
Maybe you could think about a film retriever instead. These little gems make it easy to retrieve the film leader from a completely re-wound film. Once you have pulled the leader out you can trim it square, then trim the hard edges off the corners. This makes the film slide through the reels really easy.
As for thermometers, I have been using an Ilford one for the past 30 years. I recently picked up another one as the markings were fading from all of the chemicals it had been dipped in. I have (for my business) an extremely accurate electronic thermometer, the Ilford ones, which read almost identically, are about 1/2 a degree C in agreement, which is as close as you could hope for. Others should be able to chime in regarding thermometers.
You will need film hanging clips to hang the films up to dry. They come in pairs, one is weighted, this goes at the bottom, the unweighted one goes on the top.
I hang my films up to dry in my darkroom on a crude but effective, re-worked dry cleaners wire clothes hanger.
You will need negative sleeve holders to store your films in. The ones for 35mm are usually 7 strips of 6 frames to a sheet. It usually pays to get a proper neg sleeve file holder as the neg sleeve holders are a funny size and cannot be stored in an A4 (or whatever your country uses) holder.
It may pay to somehow get a working lightbox for viewing your processed film, do a search for this on the forum. Anything will suffice, but a colour corrected (eventually) one is the best in the long run.
For cutting film, comfortable scissors
Mick.
Ps:- I just re-read your last post, have you also remembered to acquire a second reel :rolleyes: