#1. I like the "uses up chakra" idea more...because any jutsu would take up chakra, even kakashi can't use raikiri/chidori "once a day" without any cost to his chakra...his chakra is just GONE after (how many? i forget)
#2. Chakra and turns should be spent to master the jutsu, much like a house (takes work and time and chakra used up for failed experiments)
Editing them/upgrading should also cost more turns+chakra
#3. Multiple jutsus should be allowed some people might want a weaker one against small fry (level 1-5), a medium one against medium opponents and a stronger one for strong opponents and a super strong one for the flawless oro kill
That way they don't waste 10 chakra at level 5 against a level 5 guy, they can just use 2 instead and still kill it.
#4. I think only kage+ should be able to create jutsus, the only guy that could create them besides hokages was Kakashi who was an Anbu Captain (yes, he actually was, until he gave up the role for some reason and went back to being a jounin.) The only justus that we know who invented them are rasengan, summoning jutsu, the tree jutsu that the 1st invented [sorry i forget the name, but look in the sarutobi vs orochimaru battle and it's there] and chidori/raikiri, and 3/4 were invented by kages (yondaime, sarutobi and shodaime respectively).
I would say hokage, but then I realized Kakashi was only an Anbu Captain (and not quite as strong as the sannin
)
So, I think the DK requirements should be gotten rid of, just turns+chakra+gold+gems to create...
#5.
Maybe also
Buffs:
Note: attack/def means attack OR defense, not both (they are seperate things, but i just put them together for my own sanity)
() +1 attack/def (1,000 gold:1 Gem)
() +2 attack/def (2,000 gold:2 Gems)
... (I'm lazy and don't want to type it all out)
() +40 attack/def (40,000 gold:40 Gems)
Other:
() Invincibility 1 round (10,000 gold:10 gems)
...
() Invincibility 10 rounds (100,000 gold:100 gems)
I also don't think that any justus should be usable during pvp's, because the opponent can't use them, giving attackers an unfair advantage.
Just my 2 cents, if I think of anything else I'll add it...