In Naruto chapter 618, all the souls that are bound inside the shinigami of the shiki fuujin were pulled out by Orochimaru. It includes the souls of the four previous Hokages. Now, before his death, Minato was able to seal half of the nine tails chakra into his own. Does it mean that he is much stronger than he when was alive? Does he have any chance on using the kyuubi's chakra for himself just like what Naruto did?
The resurrected Minato is stronger than when he was alive, but that is due to the properties of Edo Tensei (unlimited chakra, near-unlimited stamina, and automatic regeneration of any damage taken).
Minato does not have Kurama's chakra inside him. The Yin-component of Kurama's chakra, sealed by Minato, is still inside the Shinigami's stomach. Shiki Fuujin does not seal the target's soul into the summoner's soul. They are both sealed together, but independently, in the Shinigami's stomach.
This can be confirmed since Orochimaru first recovered the soul of his arms and then the four previous Kage at once. If the Shiki Fuujin sealed the target's soul into the summoner's soul, he would have to first recover Hiruzen's soul, and then the souls of Hashirama, Tobirama and his arms from Hiruzen's soul.
Minato does seem to have Kurama's Yin part inside of him. As proven by the recent chapters. Which undoubtedly proves that he's much stronger compared to the way he was before his death.
Note: This answer is based on events seen till Chapter 623. The answer may become obsolete after subsequent chapters.