1. Is Dice RP a lot more complicated than Literature RP? is so please state the reason?
It is by default because you're adding an extra layer of mechanics on top of all of it.
So all normal forum RP rules apply as well as the rules for Dice RPs.
2. What's do we attributes need to have as a GM? Like strict or...?
It varies greatly on the System you're using.
D&D has STRENGTH, DEXTERITY, CONSTITUTION, INTELLIGENCE, WISDOM, CHARISMA.
GURPS has Strength, Dexterity, Health and Intelligence.
etc.
If you're making your own system just choose whichever attributes you want.
3.What makes a Dice RP fun? I know it's a relative answer for each person...
On the forum?
I'd have to say it adds level of realism/balance to it.
In forum RP's everything is subjective, "Can I do _______" is always up to the DM simply saying yes or no.
But with a Dice system it's a clear mechanical issue, so it's up to your stats and roll of the die, which almost eliminates the risk of God Modding or misbalanced players.
On top of which it adds some unpredictability, instead of the players simply deciding what happens the dice play a roll.
You could spectacularly fail at something or vice-versa.
Lastly it forces you to put some limits on the character.
For example someone can't make a CS simply listing a shit ton of powers, there's normally a point buy system that limits them.
Forcing them to make starting builds within a certain power range, and if they want more they need to earn it within the RP.
4.How to lay Dice RP out?
In all honesty?
The forums are ill-equipped for it, you're better off just doing tabletop online with something like roll20.
But if you do want to do it on the forums?
Treat it like a normal forum RP, just with dice rolls and point buy character creation.
And set up a means to roll a die multiple times per post (which usually means finding an off-site roller instead of using Iwaku's).
Otherwise all your posts will be stopped short because the person will need to it anything they do anything requiring a die roll (swing a sword, tell a lie, recall a certain fact etc.).
This either leads to an insanely slow RP (with short posts at that), or means a shit ton of multi-posting because people need to make a new post every time they do something that requires a roll.
However finding a means to roll multiple times in one post?
That means you can roll for that specific action, and then keep going in the same post without halting.
This however comes with it's own concerns.
Because Iwaku's dice roller is designed in a way to prevent cheating by only letting you roll after the post is made*.
If you use a roller off-site you won't have this safety net (unless if you use very specific dice rollers), so you either make the rolling more complicated, or you rely on the honour system.
*This add's to the issue above about multi-posting, because now you need actually submit the post and roll before even knowing if you succeed or not.
So I would either have to go:
->Posts "I swing my sword"
->Roll Die
->Findout Result
->Choose between editing post to account for the roll, make a new post to account for the roll, or wait for a reply.
->If you continue, note that doing another roll action require's another roll, probably requiring a second post.
5.Is the game mechanic diverse from one rp to another?
Very Diverse.
You got your High Fantasy like D&D that at later levels makes players almost invincible, Call of Cthulhu where you're going to die... there's no debate, it's just a matter of when, how and will it be from insanity? Your GURPs which is brutal realistic but can be in any time era etc.