Trading bot uses technical analysis, which might work depending on which coins that you choose. Even human also use TA. In this sense, a bot should be better than human (as long as the parameter/indicator is set correctly).
3. Crypto news channel also drives the fluctuation the price such as the sudden announcement of ban of crypto asset by China or any other countries.
What you're talking about is basically fundamental changes, which as you said, is not detectable by bot which mostly use TA.
Depends on what bot that you choose. In theory, any program is perfect before you found the bug.
Not really, open source bot depends on how you set it up.
If you're doing day trading, it's just the same thing. You can run your trading bot on VPS if you want.