A few issues with Ranger. Clear them up?

[Hoshi]

I love ranger too and find it to be lots of fun. The drawback is that you will almost never play it because as you pointed out it is useless in abyssea. People will argue that it can proc lots of blue !!! but so can mnk + whm during blunt time and your ls will probably find other things to do that require red or yellow !!! outside of blunt mode.

[Mirabelle]

In order for a SAM/RNG to hit Sidewinder reasonably well, they need a ton of RACC which they don't have as much access to. So while the RNG is stacking RATT and STR, the SAM needs to stack RACC, diminishing damage despite more freq WS. Soboro SAM/RNG is fun but it will be superceded in damage by a proper SAM/WAR with a magian weapon.

As far as RNG in endgame, the job will likely have to wait until everyone leaves Abyssea for the "Next Great Thing" TM.
Inside Abyssea its role is quite limited. I haven't been out on RNG in months.