Is it possible to acheive a level where after you die you can reincarnate yourself at will while retaining all your previous memories as well as be able to travel with your spirit from this world to all others on the spirit plane at will with no restrictions?
Yes and no. You do reincarnate at will, as does everyone else, but it's your spirit's will. Your spirit will regain all previous memories after your death, although not immediately after your death. You will not take any memories into the next life because your brain in that life(your physical brain) was not present to experience the past lives. However, through meditation it is possible to gain the memories from past lives. Those memories are stored within your soul.
There are also stories of people being capable of shapeshifting, that was covered in another thread. There are stories of zombies, space-men, aliens on Earth using the internet, etc. Stories mean very little unless there are facts to back them up and I've yet to see someone prove that they had memories from past lives.