This is what happens when you basically stick to the bounty threads: you miss a whole different world on the forum, filled with knowledge and, at times, something complementary called Merits …
-   To earn merits, “simply” make posts with decent enough content, with a certain frequency, and that come as natural to you and your interests. Not much else to it to begin with.
-   The above is the “legit way”.
-   The basic use is to rank-up (along side Activity), facilitate participating in some campaigns nowadays, and giving the ego a good old rub every now and then.
-   Real use as above.
-   Higher ranks do support Newbies (see updated information on  [TOP-200] Members who support newbies - Thanks! ).

The best way to learn more about it is to simply take a look at merited posts. Most of them should have something of interest to them that called the Meriter to merit them.