I guess you sold your Bitcoin too early and are now in emotional pain, which is clouding your judgement (or maybe you are a no-coiner, in which case, it's not too late to expose yourself to revolutionary tech and take a mall position)
Bitcoin is not expensive for transfers. Try sending hundreds of thousands (or millions) to another country using a bank account. $25 for this is amazing. It might not make sense to send small amounts however, but there are other cryptos that work better for this.
Bitcoin is only as secure as your own security. If you know what you are doing, the chances of it being stolen are zero. If you dont store you private keys properly , then yes, you could compromise your account. If you are worried about being hit by a bus, then there are procedures for passing on crypto to others with a few lines of code.
51% would be ridiculously expensive - I would be amazed if anyone other than a state actor could carry this out. (also not sure where u are getting your info from, but BTC network has never been compromised in 51% attack). Even if a 51% was carried out, then the next chain (Ethereum, most likely), would take over the place of number 1 crypto. You can't kill crypto at this point.
Portable - it is much more portable than a bank account. While you can carry a bank account across borders, there will be questions asked. e.g. Chinese businessman wants to escape the country with millions - they cannot - their account will blocked to prevent capital flight. BTC fixes this.