It is going to depend on the pen section, but another useful tool is a desoldering bulb. Just pull the tip out of the bulb and you can use it similar to the bulb syringe, except it will go over the end of the pen section rather than in the end of the pen section. It works great for some pens, but is useful to have in your pen maintenence tool box. I'd also add some jewelry polishing cloths for wiping down the pen exterior.
I don't know how many people this would help, it's kind of a specific case for people with a 3D printer, but I designed and printed a modified clothespin with stabilizer "legs" splayed in an "X", and an extension at the clamp area to better hold empty cartridges and converters perfectly vertical so I don't have to hold them while loading an industrial syringe with ink from a bottle to make refilling those tubes easier. Another thing I do, don't really know if you could call it a "tool", but I bought some clear plastic test tubes with aluminum screw-on caps from Amazon that are about 7 inches long, and about 1 inch in diameter. Great for storage of pens that for whatever reason don't have nicer packaging cases. I print a card 1"x6" with text boxes for the brand, model, color, nib specs, ink fill methods, company where I sourced the pen, and notes on removing the cap, disassembling the nib section, and body of the pen, and include the card into the tube, so years later I don't have to worry about, for example, twisting a nib that I was supposed to pull straight out. Also, get a plastic toolbox with an upper tray for all your cleaning and maintenance supplies. One with a few fast-access bins integrated into the lid for commonly used tools is pretty handy. If you're still early in your pen habit, you can even keep your ink bottle collection in the lower compartment, but don't expect that to last too long. 😏
I agree with all you said. I would just add a rubber grip (like the Goulet grip) and wooden toothpicks to put the silicon grease in the barrel of piston filler from the section, possibly too a feeler gauge to measure the distance between the tines but the shims are good enough I suppose. Lastly I’d mention that you would want a couple of bulb syringe one like you shown and one with a shorter neck so that you can put the syringe around the thread for the section to clean it (typically I do this with Japanese pens).
I practice Chinese Calligraphy using fude fountain pens and I find it much easier to get line variation if you put your paper on a thin, soft pad like an oversized mouse pad that I bought from Amazon a month ago. I love writing Chinese bible verses in Calligraphy style and I find it very stress relieving and peaceful.
Great list! I will add a rubber grip. Once in a while, a pen with a small section that's slippery is too tough for me. I think a few rubber bands could work, but I like the rubber grip I purchased from Goulet.
