There is already a more popular thread for that question in the "Bitcoin Discussion" subforum:
https://bitcointalk.org/index.php?topic=1843355.0Perhaps you can ask your question there and close this thread.
tl;dr: PoS is very, very improbable because it would change the whole consensus model. A hybrid model like you propose may have better chances, but I don't see it short- or medium-term.