Again there are issues with Obito, he had the Rinnegan and the Sharingan. Its possible this formed some sort of interferance I don't know but i do know that Obito isn't a great example.
You keep talking about DNA, Uchiha DNA is linked to their BRAINS (spiritual power minds!) not their eyes (the Sharingan is a result of the special chakra effecting the optic nerve). Senju DNA is linked to their BODIES not their "normal" eyes as you so put it. The DNA we are speaking about are a manifested forms of Juubi power. Genetic modification to incorporate senju or uchiha dna into either an uchiha or senju can potentially produce a Rinnegan. But that yin yang originally came from the juubi so the Rinnegan must come from it. There is no other way to explain it. So going to the source of that power must produce similar results.
-----------------------------
Naruto & Sasuke Bloodline:
Sasuke exemplifies the elder son bloodline. The most advanced example of the bloodline alive today, EMS and dark chakra comparative to Madara's own. Strong Chakra with a potent Yin component.
By comparison the fact is that Naruto hasn't expressed any evidence of Senju powers at all. Senju powers involve the Mokuton, apparent talent and massive Yang power. Are massive reserves even a part of the Senju bloodline? Strong Yang doesn't mean massive reserves.
The only thing he has shown is massive chakra reserves and powerful yang, no Mokuton, no real talent. All he has ever had going for him is the influence Kurama has had on Naruto's body which resulted in massive reserves even greater than his normal Uzumaki heritage would supply. Alongside that the ability to manage these reserves, however is that a talent or is it just a natural side effect of his situation. The massive reserves of yang chakra can be explained as being an influence of not only Kurama's unbalanced state but also Naruto being a dumb ass. Ergo his Yin energy is limited because of his own stupidity. That doesn't sound like a bloodline to me does it...Hashirama wasn't a moron was he, his Yang power was just much stronger than his already formidable Yin.
Also how can the Uzumaki be of the Senju younger son bloodline. No senju have ever been shown to use Chakra chains of any form which seems to be an ability that Uzumaki can unlock. If the senju were the root of the Uzumaki bloodline then wouldn't Tsunade (a far superior ninja) have unlocked such abilities when faced with loosing her beloved family? Why would the Leaf village send off for an Uzumaki to seal the kyuubi into? Why not just use a Senju if they have the same blood? No something doesn't make sense there about that.
Ultimately I'm not convinced that Naruto will gain a "chakra" upgrade here, What kind of upgrade could it realistically be? Obtio gained great speed and the black stuff. But Again if he gained even a portion of that ability for someone like Naruto its STILL a power up that's mostly useless. Madara isn't going to be beaten by speed in this case.
I challenge you to come up with a realistic power up based on chakra that can logically make sense and be useful right off bat in this situation.
I undertand largly why most people think naruto will simply get a stronger "cloak mode" instead of a ability that requires technique ( mokuton, rinnegan, etc.....) The argument against the notion that naruto gets a ability like rinnegan is that it wouldnot do any good because of time, however the truth is that we don't know- in manga time insot always an issue- look at goku and the hyperbolic time chamber, or ichigo and the dangai. What if naruto goes through some training in the kamui dimenseion- multiplied by the growth factor of the shadow clone justu?
-It's entiterly possible that naruto masters new abilties quick through a training session, furthermore kishi hasnot seemed to mind pulling abilies out of no where. When obito gained the juubi's power, obito mastered his new form very fast, and madara controlled the juubi instantly. Obito didnot learn how to make/use the omnyouton orbs, he just did. he didnot need to learn how to use the bijudama flower or the sun god barrier- he just did. - if obito learned/gained all these abilties whats to say naruto can't. -I personally like the theory that when minato and naruto merged chakra they gained some of each others memories ( like shadow clone returns memories) and thats how minato gaines SM. But if thats true, what when the kyubi chakra returns to naruto ( from ninja alliance) he gains the collective skill and abilities of the entire shinobi alliance.
-truthfully, this is kishi's manga -anything can happen - from time dialation ( thousand years of training) to mastering a new incredibly technique vary quickly ( obito and omnyouton, Sasuke and blaze release ( when did he have time to train that, he has been laying in bed)
Now, onto your next bit about heritage and bloodline- yes I agree with you about how close Sasuke and Madara and the older son- Eyes, abilties, etc....
However with Naruto you have to be a bit open minded. We don't know enough about the senju to say exactly what their bloodline abiltiies are-other than hashirama. -Saying senju=mokuton isnot really accurate, as far as we know only hashirama could do that.-furthermore the bit about powerfull yang- again only really applies to hashirama. We have no idea what was so special about the senju, that made the uchiha defect to their side.
-We do see the uzamki in naruto though. - only females have shown chakra chains, so just because he can't use them doesnsot discredit his heritage. His lack of seal mastery is interesting, but seal master seems to be learned so perhaps Naruto has never had the opportunity to learn anything? So far, Naruto has his uzumaki heritage's vitality + his former status as a jinkuriki. your right, Naruto hasnot shown much relating him to the senju, unlike sasuke who mirrors madara. However, again, we barely know anything about the senu. hashirama and naruto seem vary similar- sure Naruto has never had a formal education, didnot have parents raise him, lived alone- so he acts like a idiot but he has his moments, like is father.
Your right, even if Uzumaki and Senju are related- its distant, not direct. However, we don't know minato's heritage. (Blonde Hair, any other senju's have blonde hair + he is a mirror of tobirama + Jiriaya has white hair )- see any possible relationship between Minato, Jiriaya, tsunade, and tobirama here?? Just a possiblity.
A probable chakra upgrade for naruto would follow with how obito transformed- omnyouton orbs, and mokuton bijudama trees. However, personally if kishi goes that way I would be fairly bored.
My personal favorite upgrade for naruto would be rikudo abilties ( omnyouton+mokuton trees-bijudama) and he gains some of his fathers abilties because of chakra share.
-Is this enough?- yes. Most people don't realize how powerfull hiraishin + mass shadow clones are.
It's obvious that Sasuke and naruto are going to counter madara. It would make symbolic sense. Madara is the sage, with pieces of himself in conflict- most likely Naruto and sasuke are going to work togethor with (Uchiha and Senju) abilites. thats what the symbolism says and knowing kishimotto thats what he is going to do- does he care about your opinion
-The truth is that the forshadowing is there - ( did obito being tobi not have logical problems) - I if were you I would prepare for illogically- Naruto getting six path powers. -there is a good chance this is what kishi has in store ( he has alot of hints for this) and he doesnot care how he gets there.
-Don't be surprised if in a week or two your one of the only people who think its bs- and everbody else is pointing to all of kishi's "forshadowing"
-The biggest problem with logical thinking is that people in nature are irrational beings. Kishimotto is just as irrational as anybody else. Not only that but he specifically has a history of irrationality with the Naruto Manga.
-My true answer to your question is that logically, neithor sasuke nor Naruto can do anything to even touch Rikudo madara. SO, logically Naruto doesnot get any power up and before he returns to the real world Madara already crated a bijudama and killed all the shinobi.
Shadow clone jutsu is an OP cheat tech. Dat Tobirama 
are you trying to act tough or something?
I seem to have forgotten what post you mean.
