This what I like Crypto, It gives us the full control over out funds, this is why third party shouLD not be a choice now. Knowing that we could publicly see the code, we can have assurance that are funds are all safe and no one is making out of it. Instead of storing of fund from somwhere better choose an open source wallet like Hodler wallet, this kind of storage will not let any amount to go from somewhere unless you make an action.
Without a doubt bitcoin payments methods can be consider as very secure when considering such facts because fiat related payments specially which are done using credit cards through banks there are always extra payments hidden to cover there service and for them to gain more money through our purchases but in bitcoin there is no such things and like you have mentioned no payment can be done without the owners action and that is why bitcoin is a best payment method