Incorrect.
All Uzumaki are shown to have incredible body and physical prowess, in fact Naruto is actually weaker than most Uzumaki we have seen thus far.
His own mother lost Kurama during child-birth but still had enough to keep going on, while Naruto fainted right after losing Kurama.
We have not seen an Uzumaki who was fully trained by the clan so saying whether they don't have speed is still ridiculous. Don't fight the plot in where the author had barely given information, it's either yes or no.
Also incorrect. Tobidara created Flying Thunder God with powerful seals, as shown in the Manga the Flying Thunder God of Minato's version uses even more powerful seals (Cough Uzumaki), but what has yet to be confirmed is whether or not Tobirama learned from them aswell.
The reaper Death seal is an Uzumaki technique, as Orochimaru needed it to get to the Uzumaki shrine. Hiruzen also learned that technique, Minato aswell. So you can clearly see the foreshadowing here.
The Uzumaki are real monsters.