Hagi said:
Well there's not many non combat aspects of it, there is crafting where you get materials an have a npc make stuff for you like armor or weapons, or if you want you can just train in a profession and do it yourself. there was also a snowball throwing mini game once but it sucked and is not here any more.
If you want other activities besides fighting you can always play the sequel mabinogi, not sure if a sequel is the right word though considering this game came out in like 2011 and mabinogi was out in like 2003 but vindictus is still a prequel to the game, hell in korea the game is called mabinogi heroes.
Anyway, no the instances are not a major problem, basically how the questing works is that you first get a quest from a npc, then you go to a battle board, which basically lets you choos which instance you want to go to.
once you have chosen you get to a boat or you wait in town for a party to form, unless you want to go solo in which case you just hit the start button and voila you're in the dungeon fighting gnolls.
usally the quest consist of, do this dungeon, with the occasional item finding quest which can be avoided pretty easily using the market place.
now about raiderz, its like tera, i mean id almost call it a exact copy aside from the art style, that and raiderz have been free to play all along mean while tera has only recently begun with the free to play stuff.