I’m not a heavy twitter user so perhaps my experience is limited, but the actions I perform with the mouse are: Scrolling, click to view replies, click to rep

I’m not a heavy twitter user so perhaps my experience is limited, but the actions I perform with the mouse are: Scrolling, click to view replies, click to reply, click to retweet, click to like, click to view hashtag feed, click to view persons profile. All of these things could be done efficiently with the keyboard (theres also no real reason to not still support mouse for the people who prefer it). I use the online checklist tool Checkvist.com and checklists are surprisingly similar to a linear feed like twitter. I use it almost exclusively with the keyboard, including editing, reordering, creating new items, tagging, colouring... Its super efficient and comfortable. There is no reason why you couldn’t have similar navigation and interactions on twitter. Personally, I find your outright dismissiveness of a keyboard-centric UI for twitter to be laughable shrug