Security concern is necessary for any application whether you ship on your own datacenter or on one of the cloud vendor's platforms.
Many of the same concerns you mentioned needs to be address in either case. But at least with cloud vendors, you don't have to worry about physical security for example, but then, you are putting a lot of trust in them (like they don't share your data with others). But it is reasonable to assume that Google will do a better job at Physical security than you can for example.