Expect ethereum to be 250 + usd on or before 8th MARCH 2019

What's the relevance of that date?
Is their any big news in March 8 so we will see ETH to raise that big?

I tried to research in the internet but I don't see any event that would tell why the price will rise.

https://www.coingecko.com/en/explain/ethereum_constantinople_hard_fork

Does the fork alter substantially the mining to an extent that miners not on the latest software would need to update to handle the new fork.   Or is the largest apparent change for those miners just the reward alteration and difficulty changes, ie. business continues

I think a change to POS is likely correct so long as ETH remains as at least as capable afterwards as it was on POW

It's possible even without a BTC move but I don't believe that it will happen, BTC can lose so much dominance because every alt will pump if ETH will make such move

I'm pessimistic, it's becoming a reality. the current price is $137 and it is impossible to go up to $250 in less than one month. I personally have a target of ethereum prices at the beginning of the month of $ 200. if this can be achieved I think there will be many people who are happy

Whole altcoins are still following bitcoin and ethereum too. I can't deny if bitcoin still hold the main key to the altcoin. Ethereum can give a little impact to the price of altcoin but it's not so big as bitcoin dude.

Proof of Stake is always better kind of Proof of confirmations.
Because the kind of proof can better protect global environment.
Staking requires and consumes less energy, then less green house gases emitted from staking industry, than what happens with mining industry.
The problem in months to come after the hardfork is the risks of price's fall.
There are so many coins witness drops after switching from Proof of Work to Proof of Stake.
Anyway, I believe that Ethereum can make a big difference, as always.

It's been ages since I last mined ETH but did you by any chance tried using Nanopool? If not give it a try maybe?

I agree with you on nanopool. So far so good. Currently mining ETC, about ETH after the fork still have many people doubt about ETH switch to PoS. Still waiting for some good news about it. All the best for ETH and ETC.