Thanks for your long and thoughtful post.
I do wonder though if you are confusing bitcoin as a currency with other financial services. Reading through your post I think there are three themes in what you are saying:
A) bitcoin is not as secure as credit cards.
Bitcoin is like cash rather than a credit card. Just like cash its not fundamentally secure, if I leave a wallet full of cash on the seat of my car its likely my car will be broken into and my wallet stolen, if I leave a wallet full of bitcoin on an insecure device its likely it will be hacked and stolen.
This is why card cards can charge the fees they can. You pay them through fees for the extra safety they offer of being able to cancel transactions which if you made with cash the cash would gone. There is nothing that stops a credit card company offering the same service using bitcoin as the currency rather than USD, Im fact you probably will se that in a few years.
B) bitcoin goes up and down in value
Right now bitcoin is new, and we dont know if it will be the crypto currency that survives in the long term. However in the long run a deflationary currency like bitcoin will always outperform holding money as cash, as the value of USD drops consistently year by year as more is created by the financial system. Bitcoin is not a stock, it doesnt add value and pay a dividend like a company would. If anything its like gold, its value goes up as other currencies go down in value over the long run.
C) the infrastructure around bitcoin is not mature
Right now owning bitcoin is harder than owning cash or a credit card. Crypto currency is only going mainstream now and its going to get a lot easier to use in the new few years as the financial services industry adds more products on top of it. Already this year for the first time people who use investment banking services can open a bitcoin account, in a year or so most investment funds will own at least bitcoin. The mature products and services you are looking to use are on their way, but by the time they are here the chance to own a whole bitcoin for the average consumer will have long gone.