Cpu pre-renders the frames. It can only pre-render so many frames in a second, that's your max fps. Nothing a gpu can do to make a cpu work faster than it can. The cpu sends those frames to the gpu. The gpu paints the picture according to detail settings and resolution. Sometimes the picture is easy, and if the gpu is strong enough, you'll get max fps. Sometimes the picture is really intensive, like fields of grass or explosions and the gpu can't paint as much per second. So fps drops. Anything that can affect the fps is before the cpu. Game code, slow ram, slow storage etc.
So if the i5 7600k is at 3.8GHz, and the i3 7100bis at 3.9GHz, in CSGO, they'll be almost the same potential fps. Somewhere up close to 300ish. Then it's upto the gpu to get 300fps on the screen. That old 750ti struggled to get 200fps at your detail settings, the 1050ti is somewhat stronger and should be able to get closer to that 300. Just remember, on a 60Hz monitor all you'll get is 60fps, but it'll be a solid 60fps as minimum fps gpu output will be higher than 60.
Reset bios on asus mobo's is easy. At boot, soon as you hit the power button, start mashing (not holding) the Delete key or F1 (it changes according to the actual bios, some are F2 or even F12). If windows starts, you missed it. When you do get into bios, hit F5 and that'll load factory optimized default settings. F10 to save and exit. That'll reset any changes made in the bios to default settings that wouldn't normally get changed with just a hardware swap.
You can only overclock Intel mainstream cpu's if you have A) an unlocked 'K' series cpu and B) a 'Z' series motherboard. You have to have both. The B series mobo's have a locked bios, so no OC options are available even if the cpu is overclockable.