All of the Marian dogmata are in Scripture as it currently stands. No “extra books” are necessary. You simply aren’t reading or understanding Scripture correctly.
No they are not. Catholicism has used allegory to see these.
Mary had children with Joseph so the dogma of perpetual virginity is out.
Mary confessed she needed a Savior and offered the sin sacrifice after the birth of Christ so her immaculate conception is out. Catholic apologists have even admitted there is NO SCRIPTURAL support for this.
We have no record if Mary died a natural death or not. Catholicism has "assumed" (pardon the pun) she was taken up though we have no record of this.
The first two can, and have been proven, to be incorrect from a Biblical perspective. That leads me to believe the assumption is also wrong. In either case there is no conclusive proof. In situations like these it is best to go with the natural flow of life. Mary died and was buried in a normal manner.