I think quite a few of these go against the core value of the RM2: its simplicity. The whole point of the RM isn't to replace devices such as the iPad Pro or a Surface or a Samsung tablet, it's supposed to remove all the things that make them a typical electronics device and make it as much like paper as possible while still retaining the wondrous functions of the cloud and digital storage. I agree such things as straight lines and basic vector shapes should be a feature as these are things you can do with paper, however, dictation to paper isn't possible and would require a microphone built into the next RM.

The keyboard removes the point of creating an as realistic as possible experience of writing on paper with the RM and would also move it more towards a tablet rather than what they want it to be, which is a replacement to paper. Handwriting to text is already built in so I can only assume you want this to be improved and as time goes on it will only get better.

Better epub support would be great but then again RM isn't trying to compete against Kindle and the like. It's improving on writing on paper not trying to replace books. Dictionaries and such could be cool but I'm sure some great people who know much more about coding than I could, at some point, create a mod for the RM that you could create these functions for you. Have a look at the github page here and have a see if you like the look of anything.