well, there are a lot of small things in game that could be changed to better, here are some of my opinions about it..
Tamer's Pet is kinda weak, even for MR, its should be a little bit stronger.
New set, Quest for New set parts (DS Set Piece) is a little hard (harder then its should be) 250 days for Armor,200 days - Belt... u have to decrease the amount of DS Set Pieces needed to exchange or increase amount of times u can exchange DS Set Charm for Pieces.
Upgraded Amulet/Ring, at "Amulet Rings!" NPC u need an Dragon Eye to get Upgraded Red Dream Amulet/Ring, but as i see it's not currently exists in game. (there's written that its could be taken from Donate, and i think it's shouldn't be in Donate Shop, better to put it in Game, drop at Boss/Mob with low drop rate, or an Quest for it).
DS Set Charm, will be good to increase amount of Charms could be putted in one pack, to 99 or 200.
Vote Shop, there is Competition Bonus Pill 1pcs for 5 Vote Points, and its kinda useless, when u can take 5 pcs daily from just Evil Tao Beard, and more with other Quests, or even from mobs in Universe Village, so increase amount of Cpt. Bonus Pills would be good (to 10-20). also would be fine to add some more items in Vote Shop, such as GMB,Gold Box,Titanium/Lucky Stones... and add Dark Golden Identify Gem too, somewhere even TP Shop, for players who bought or will buy DG Dual Weapon.
Golden Diamond in Donate Shop worths too much i think, i don't think that anyone would buy it, and its also only allowed till +9 rank, change it to +1~+10 or decrease price for a little would be better.
Credits of SFC (Quest at Ring Suits! NPC) gives 50 Reputation Points, and u need 2-3 days to take 14 Sacrifice Stone... decrease amount of Sacrifice Stones or increase amount of Repu Points will be good.
and won't be bad to add Piece of * Heart at Sacrifice Stone Maker NPC Quests.
Well, That's all for now, hope u like any of them.