1) They already have it in 35mm - give it a go if you want to try
2) Tungsten-balanced = natural colours in artificial light. This is what white balance is for in digital.
No filter is required for natural colours under artificial light but a filter will be required for natural colours in daylight. Daylight-balanced film has the opposite issue. Shoot either without filter for unnatural colours - the same as having the white balance setting wrong in digital.
3) I have no idea what "not optimised for the range of shutter speeds in still photography" would mean. Did they mean reciprocity failure with slow shutter speeds? Hard to see that being a practical issue with an ISO 800 film. Particularly not one with the sort of latitude this is said to have.
Commentary:
http://www.japancamerahunter.com/2013/08/excellent-film-news-new-film-from-cinestill/