of course you can use Blueprints all the way. The big thing to think about is that you should still know how to program. Things like Casts etc, also you shouldnt put your game logic into the Tick function (Blueprints make it very easy to “draw” bad code).
Regarding C++: With the Unreal way of C++ you wont have to care much about memory management, but it is a bit hard initially to get things done and learning how to use the Engine macros correctly.
All in all, i am currently doing an archery game in VR with pure Blueprints, and the performance is not an issue with Blueprints (but with everything else ), and it works perfectly so far.