I'm still using MEW with private key. Luckily my wallet is safe until now. After reading your post i think i will find another wallet to use.
If you are still safe, there is no need to look for another wallet, I also still use MEW until now using private key and I don't think to move to another wallet. The most important thing is you really keep your private key in a safe place, so I think it will be fine.
Yes, just keep the private key safe. I believe we will always be okay with MEW. I have been using MEW for many years and have never had any problems with it, recently I moved to the TRust wallet because it is so much more convenient.