Only just got new version. Why is instrument select not shift and up/down arrow anymore and why can’t I change it back in preferences???
Think I might go back to version 1.5 its doing my head in!!!
I’m sorry for your loss in sanity. It happens to me sometimes. But have a few beers, sit back. Listen to some Enya. Inhale, exhale, inhale, exhale … “calm blue water, deeep blue seeaa”, zzz, zzz…
I’ve spoken to a few people who had trouble adjusting to the renoise swap-around, so I know you’re not alone - think about it though; in Windows, shift-arrow is for selecting, so logically it should be the same for Renoise. It was a design ‘mistake’ to begin with …
My advice, get over it, and accept that your brain will eventually adjust. 
May I add that keybindings in Renoise are fully customizable?
Go to Preferences and set them as you wish.
It’s keypad - and + now and that is objectively viewed a far better choice than the shift up/down arrow combinations.