I'm curious why in this game you have mind and int. Int for wand, a long range magic type weapon. Mind for staff a support type weapon. Yet both of them sucks. I wonder if it's possible to remove one of these stat, so that Int/Mind will increase the damage of wand and staff. Just like dex increase the attack of bow and twin sword.

Spell damage was nerfed in CBT. This most likely will not be the case for Official Launch.

Plsno.

In my opinion merging mind and int would be similar to merging vit and pow. Which isn't really that great.

As it stands both mind and int serve different purposes aside from weapon affinities and I would like to keep them that way.
http://onigiri.wikia.com/wiki/Stats#Wis_.28Wisdom.29:

Here have a wiki page to know what's up.

I don't think either Mind or Wisdom is weak. Mind fills a utility role more than anything else, it's great for any character that doesn't want to go full DPS, since it gives a lot of sustainability between the SP and heals. On the other hand, characters that focus on Mnd as a primary stat (aka 100 Mnd or something ridiculous hence having no damage whatsoever) require an effective party to be effective, since these are the only characters that can reliably resurrect and sustain 4 other people. Wis, or rather wands, were weaker in the CBT since wands are highly reliant on Magatama and highly ranked skills to output damage, all of which were hard to obtain in CBT. I would go as far as to say they have they highest potential damage of all weapons, in exchange for the dedication to get to that point. Alternatively once player shops are out you could buy these from other players for a (probably) hefty sum.