1. After you hit A1 at serpents you can go on the last map cave from gate master and grind at first mobs, from A1 to A5 (to equip your A5 gear) then you grind at the next mobs from that cave.
2. I did not know either, but last night i've entered for the first time in a war (A10-A12 war) and there was some bosses that looks like dragons on 2 legs, i've managed to kill 2 of them and i droped 2 soe (12%), 2 bs (9%), 2 ds (6%), 2 tins (3%) a bounch of rares, money purses and silver too, so i guess there are bosses on every faction map and in other places too but you need to hunt them :D
3. This is hard man trust me, skills that you drop you can found on npcs and ofcorse you can't sell them with the price that npcs are selling them, and you drop like 4th and 5th skills wich also are not so popular cuz everyone wants to buy and use 6th and 7th skills, and also other lev60 skills like HS, HB, Garuda. Rares that you drop also they are useless, asuming that everyone from the server have the same chance at droping as you, they complete every adept rare gear from grinding and they don't need something else, just like you..you grind for drops, experience and silver, you will use that rare gear that you dropped, you can't sell rares on npcs, you can't ask like 1m or 500k for clean rares cuz everyone in the game have them and they are useless, so for this question im afraid you need to farm that silver hard as you can, grind your pet to 100% so it would be easier to farm silver cuz he will pick it up, well maybe you will drop some elites wich you can sell them for pretty much money :D
And another tip (i forgot), when you are grinding pick up every uniques that you drop (first pick up every unique, when you are full inventory, and you drop a unique weapon, replace with an armor, gloves or boots from your inventory cuz the weapons you can sell for much more money than an armor, glove or boots its like 2.5-3.5k silver difference) and also if you drop a rare (except for marble and heavy sword asuming that you are a light sword user), drop something from inventory and pick that rare up and check it, in the last map's cave, every mob from there drop 2 sets of rares (first is dropping a5 and a8 rares and so on to the others), after you are full inventory or you level up'd or idk you are bored, go back in town, and sell the uniques you dropped to npcs, and thats how you make a little but important amount of money, i'm played for like 4-5 days idk from now, let's say 2 hours a day of playing, i've managed to hit A11, and made 12m silver, from uniques and picking up silver :D
Thank you for the replies guys. I am a11 now grinding in IE atm almost got 10m. What can i say. There will be some work to gather the skills and money for a33 decent gear.