Sorry for asking so many questions but I'd never figure this stuff out on my own, you guys are awesome with the help, and one of them is sorta an important matter I'd like repaired before I explode. :D

1) My armor's durability is low.

I made the bad mistake of, constantly, rushing into battles with Elegant Crabs while wearing Honest gear. It hurt, I pushed my luck, and I died quite a bit. Now all of my gear is below 30% durability. Can I fix it, and if so, how?

2) All these purple popo things in my bank.

What the hell are these things? I click on them, try to use them, and they never do anything. I figured atleast one of them was the Popo Stone to resurrect if dead, but apparently they aren't. Are they worth keeping?

3) These Dragonballs mobs drop.

Are these the tier 2 Dragonballs that you're supposed to find with the Dragon Radar? I find it unusual that I've found two in the same day. I'm not complaining, I'm just mainly asking if that's what these are.

4) My pet egg thing (Same pic as above.)
A pet egg with a tail and ears seems...underdeveloped. Does this thing ever hatch or change into a real pet? Or is it just an egg with ears and a tail? What is that empty slot on his hud picture? Is there anything else about the little thing I should know about?

Thanks for putting up with me, here's to me learning the game inside and out. :)

1) If you go to a merchant the bottom left buttons are the repairing buttons.

2) The ball-like popo stones are for rezzing. The one that you have highlighted with the little head on it popo stones will send you back to where your homepoint is.

3) Yes, that is a tier 2 dragonball.

4) The pet does not upgrade or hatch. However, you can get cooler pets than that one. The empty slot is for rings that do various things. The 7xx zeni one makes it so that people can't scan to see what equipment you're wearing. The 32k one allows you to access you mail from a distance but you can't grab items from your mail with this method. Then there are a few cashshop rings that do various things. Aka it's not that useful. Pets are mostly for fun at this point in the game.

To add on to your second question. All those items can stack with each other. Instead of having wasting space in your inventory, just pick one up and place it on top of the other.

Alright cool, thanks.
Next question: Why is the Kamehameha on the Martial Artist so...useless? Is there any point in using this, or should I just focus on my melee? I mean it's even weaker then the Tunnel Slash. ._.

it isnt useless,its very usefull,when you add knockdown he knocksdown pretty much every mob in front of you.It saved my life in game a lot of times in tough situations.