My first question is, if i copied the wallet.dat file to another disk (ssd to hdd) in 2017 would this file be dated as last modified 2014 or 2017?
You can easily test this yourself by copying a file with timestamps at least a minute old.
It's not specific to a wallet.dat file but based from your Operating System's behavior.
Second question is about pywallet, is it really safe to use it? i mean it sounds like it could be stealing your keys easily. Like what's the way of using pywallet safely?
It's open-source so you can try to check the code for something malicious:
https://github.com/jackjack-jj/pywalletMany would say that the current 4236 lines of code is safe but don't take my word for it, verify it yourself or ask for more opinions.
Use it offline to be safe, most of its major features don't need internet.
If the goal is the same in your other topic (
link);
You could just use Bitcoin Core to export the private keys from those old wallet.dat files.
My reply has the instructions on how to do that.