no apologies needed. i've asked the same questions myself
hmm, no bottleneck with the 750ti, but it's not half as good a card as the 1050.
When people say 'bottleneck', yes more often than not a CPU is holding back a GPU because it can't privde the GPU with enough data to work at it's optimum levels. That doesn't mean it won't work. But you may not see a huge improvment in FPS because of the bottleneck. It's a fine line between getting a new snazzy GPU and being able to run it at full pelt, versus doing an upgrade that won't fully be utilized because of a lesser CPU.