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).
Champion Points are earned for completing a game with a particular champion. Earning CP will allow you to gain Mastery Levels (up to level 5) in that champion and earn rewards as you progress. Points are based on your performance, your team's performance, the length of the game, win vs. loss, and a few other factors.