Sounds fair. I was just wondering if there was any already existing restrictions.Unnecessary suggestion.
Wood bios aren't Oped in general. Hashirama was powerful in the manga but that doesn't translate into the RP directly. The main thing that made him powerful was his ability to heal himself auto and that is, in our RP, very well restricted. You need to either get special training in the med school with Nexus or finish the med school to get access to that ability...and then you have it in any other bio you possess. Med school is in iself a more than enough restriction to an ability. As for Chakra Enhanced Strength, its a good, useful, powerful ability but nothing unreasonable and even Sakura bios have it. Then you have wood. Like someone pointed, Weak to Lightning. Nothing much there. Its much more powerful in the manga because of scale and because ninjas in the manga don't have 5 elements and CEs and mastery over 500 techniques like a ninja has in our RP. So it doesn't make sense to have a battle test for Hashirama. Perhaps a bio rule explaining his abilities might be added but I honestly don't see even a need for that.
Tobirama's only special ability that comes auto with him is the use of water techniques with only one handseal and no need for a water source. Edo Tensei requires mastery over Kinjutsu, something gained only through special permission and only once you have both time in our RP as well as mastery over other fields such as Fuuinjutsu and all other ninjutsu, tai, gen, etc. Its not something you gain auto with the bio. S/T in Tobiramas are nothing more than a reference. We don't know what technique it entailed and what he was capable of doing and as such he has no access to those abilities in our RP and unless Kishimoto actually explains what they were, he will probably not have them.
Itachi is just a ridiculous notion. Hes a normal Sharingan bio in our RP and his most noticeable ability (MS) requires senseiship, permission and a difficult battle test/tournament prize. So that notion is simply ridiculous.
Deidara has enough restrictions for a bio that, again, is powerful in the manga but not so much here in the RP. Lightning exists and every bio in the RP knowns it if it wants so no need to actually overestrict something just because one is unable to compreehend the difference between the manga and the adapation we do on some abilities in our RP and the context of them in it.
Tsunade has a very heavy restriction. You need mastery over Ninjutsu. That alone makes it quite restrict. Not only that but her speed is nothing that big and even if immortal, she's only immortal for a limited number of turns after which she actually loses the fight. So her abilities aren't oped in any way. She's vulnerable to speed and distance and time (as long as you wait, her abilities fade) and Genjutsu. So again, useless suggestion.
Only difference between Yamato and Hashirama in our RP is the use of Flowering related techniques (cannon and CJs). Much like Rubber is restricted to Dodai, even if he can use normal lava, Flowers and specific flora production is restricted to HAshirama and Madara bios. Yamato is left with normal wood and trees. doesn+t mean this won't change. And in our RP, because Yamato was even more popular than Hashirama, it was deemed it would be fair to treat them as much as equals as possible.