[@Mugin] Okay we're going to start off SLOW. Meaning that, you're going to stick to ONE CHARACTER for now, alright? I'm not a fan of character hoarding, especially with one being Life release and the other Dust release (Good luck having that ever validated). 

For your current character: 

-What's the point of Sage transformation if it's just a staple to compensate the fact that we've denied Sage mode? I mean it's barely used or expanded on other than some random bonus. 
Also, it's my favorite Kekkei Genkai in Canon, meaning my ridiculously biased opinion will push me to deny it quite easily if simply used as I've stated above, which it is right now.

-Water-Heavens Convergence sounds ridiculously strong. Knighthawk wanted the same power as a KG, it was righteously denied. This won't be an exception. 

-Okay for your summonings. Manda II is out of the question lololol. Why not make your own Custom Summonings instead of taking already dead characters? The giant salamander isn't that bad since Ibuse was far from being that big, so that's actually acceptable as a C rank. 

-The Customs for your summonings aren't a problem in themselves. The issue I have is that your character should be more focused on summons rather than having random ninjutsu, a Kekkei Genkai I'll likely have a hard time digesting and a bunch of complimenting summons. 

You character is just all over the place in terms of techniques and needs reevaluation. I would suggest choosing the direction he should take and stick to it, otherwise he'll end up really subpar in all these levels and be an easily defeated mess. 

I want to add that your fighting style needs so retconning, because Sage transformation CAN have links to summons but it isn't Senjutsu in the pure sense, it simply utilizes natural energy in a different fashion. Plus if you do you use Sage Transformation, certain jutsu come with it, they're not freebies. As I said before, this Kekkei Genkai seems to be just some random thing you put there just to use Natural energy when you can just be a summoning specialist (and later be some random sage that you've EARNED). 

Now for non-fighting: 

-Personality is WAY too short, like as big as C rank customs. That won't come to pass.

-If I recall correctly, Juugo's clan is a bunch of people who couldn't master Sage Mode, and became crazies. They came from Ryuchi cave, not Otogakure. 
Why would Konoha accept him in? Why would they need some random kid with an obviously very dangerous Kekkei Genkai? He's not even from a major village so exchange program is a big no. 
So he randomly found three very hidden areas that were said to be pretty difficult to find all because he wanted to be a sage? Which of course he'd fail hard since his body was predisposed to suck at it. So it's just for random summonings? Why does it have to be the Main Protagonist stuff as if he were so special he had magical acceptance from all these places just as Naruto or Kabuto had? This part is just really strange and irrelevant, you can have Toad summons without being in Myoboku, heck Naruto got his first summons by just making a contract. This kind of smells like Special snowflake syndrome. 

That's about it really. I think that you really need to re-work this because some parts simply don't add up and are just out of place. Tell me when you've decided on what to change.