well, Minato would have become the strongest hokage in no time, it was only a matter of time before he learned to pair rasengan with his element, and then he would eliminate pretty much his only drawback and jump into the top 5.
as to Naruto, he wouldn't be as powerful without the kyuubi, but he would be a much better ninja.
a. the kyuubi wouldn't mess up his chakra control, meaning he would progress much faster. he learned kage bunshin,multi kage bunshin, and rasengan at age 12, imagine if he had better chakra control.
b. with Minato to teach him, he would have learnt fuinjutsu, and possibly training to improve his speed rapidly like sasuke did when kakashi trained him. not to mention, much better shinobi sense and knowledge.
c. he would have learnt the wind element much faster, as well as his second element. which means, combination attacks with clones.
d. then, he would perfect sage mode without the kyuubi interfering, meaning he can merge with ma and pa and would be pulled out of sm after 5m/2 rasenshuriken.
in short, Naruto would be a stronger and more enduring, less smart version of Minato with a few improvements/innovations of his own. He would still have a big drive to succeed, to surpass Sasuke his rival, and his father, the strongest person in the village. and with Sasuke's abandoning the village, he would still improve very fast.
as to Orochimaru, he wouldn't dare attack Konoha, not with two kage stronger than him there. even Pain might have second thoughts