In addition to getting payments going back to your application date, you can get up to 12 months of retroactive payments for the year prior to your application date (or your protective filing date, discussed below) -- if you were disabled that long ago.
Characters will receive one specialization point at level 7 and another at level 14. Specialization points can be saved for later levels or used mid-level (the Level Up button on the stats sheet will be active if there are unspent specialization points).
For high-lvl char (85+) it does make sense. For lower lvls yeah, if it is 10+ points better just relevel the new character. To put into perspective - the cost of respeccing the entire skilltree would be roughly equivalent to 5-10 hours of farming a boss depending on how efficiently you do it.