The way you described the exit you made it sound line a dangerous narrow strip. It’s just a lane parallel to the track so exiting cars are better matched in speed when they blend into traffic.
Yes. My initial impression was that it would be narrower and faster than it actually is.
Picture 1. The new exit
Image source: http://www.dailyspor...ck-notes-3.html
Picture 2. The old exit
Image source: https://wtf1.com/pos...erous-pit-lane/
In the Picture 1 the exit looks narrow, but on the Picture 2 taken from 2018 French GP it looks much wider. In fact, the blue divider has been made thinner now so the new part is even wider than than shown in last years pic. The new "pif paf" return route back to track is roughly where the red gorilla stands.
Originally I also though that pit lane speed limit area stops immediately after the main paddock area ends. But now that I've re-checked this, it appears the speed limit runs all the way to the end of yellow concrete wall (between the pits and track). Ricard has extremely long pit lane and if they could have nailed the floor immediately after the main pit building ends, the cars would have arrived to new lengthened exit section with very high speeds. From the looks of things the surface between old and new section isn't particularly smooth, so during a wet race (which for sure is not typical at Ricard :-) there could have been some issues.
Anyway, to get the good impression on how long the pit lane now is, please check e.g. via Google Earth.