Long drivetrain compatibility: Shimano/SRAM 7/Shimano/SRAM 8/Shimano/SRAM 9/
That probably doesn't help much. Ive never used a bar shift on anything, but I cant see why not. The 1:1 actuation may make the shifting movement very narrow on the barshift (Shimano is usually 2:1ish) but once again I have no experience with bar shifters . Best to disregard this post til someone with experience comes along
If they worked at all, they'd work poorly. As wheelchairman posted, the actuation ratio is different between SRAM ESP stuff and the rest of the world. Friction mode would be your only option, and they'd be extremely touchy. If you want to use bar-end shifters, get a Shimano rear derailleur to go with it; you'll be much happier with the end result.
Maybe, maybe not. Sorry I didn't pick up on it the first time, but if you try to use 8-speed bar ends with a 9-speed cassette, you're asking for trouble.
SRAM cassettes are 'shimano compatible' meaning they have the same spacing between gears: 4.8mm for 8 speed and 4.34 mm for 9-speed. If you use 8-speed shifters on a 9-speed cassette, they won't index correctly, and of course you'd have one more gear than clicks - although sometimes bar-ends will have an extra click.
IF you had the extra click and made gear #5 the one that detents best, then you'd be off about 1.9mm at 1st and 9th. While it *might* work, it'd be almost a half gear off, so it'd work crappy at best.
The chain and crankset wouldn't matter enough to worry about. And obviously if you can get 9-speed bar-ends to go with a 9-speed cassette, there's no problem.