First I want to say that I have some Bitcoin and I want to see it go to the moon. But I have some questions regarding the reasons that people give as to why Bitcoin is a good investment. 
Reason 1: You are in control of your own money - government overprint cash which devalues the dollar, but big influential people and institutions can devalue Bitcoin with a single tweet. Bad news, issues with mining, and other things out of your control can devalue Bitcoin.
Lol, you just said that big influential people can "devalue" bitcoin with a single tweet as a reason why people should invest in bitcoin. So when they do that, just invest more. You will be helping the price to go back up and in the long run, you will also be making more profit.Reason 1: You are in control of your own money - government overprint cash which devalues the dollar, but big influential people and institutions can devalue Bitcoin with a single tweet. Bad news, issues with mining, and other things out of your control can devalue Bitcoin.
Reason 2: Nobody can take away your bitcoin whereas the bank can confiscate your cash and lock your account - should I worry about my bank doing this if I am not doing anything that is illegal?
If you aren't doing anything illegal, the banks won't lock your account. And no, if you acquire those bitcoin illegally, your government can confiscate your bitcoins depending on the law of your country.Reason 3: You can send it to anyone in the world - why would people want Bitcoin when you cannot use it to purchase in many stores? Plus ii takes too long for 1 transaction to go through.
It is because bitcoin hasn't gone mainstream yet. There are stores that you can find online that accepts bitcoin. Give it a few more years and maybe we will be spending bitcoin on physical stores. And for the transaction confirmation delay, I am sure we will come up with a solution one day.