I am a bit of a burned out simracing fan. But I am sporadically getting back into the saddle. It will take practise before you can compete but it´s like learning to ride a bike. Once you learned you can get back up pretty quickly and it improves your real world driving skills also if you drive the right simulations.
Draygonn if you want to do your wheel justice stick with Race 07 and rFactor of those titles you mention. The other ones are game pad optimized and console damaged arcade titles. I do preferr them all with a wheel but you may get a bit disappointed with your purchase perhaps.
My personal tarmac favourite is Game Stock Car. I don´t know if it will ever pick off on the multiplayer scene but all the cars are made for close racing as in everyone drives the same car just different bodywork on the V8s. Superb physics and force feedback best I have encountered and for very little money.
gravel/rally Richard Burns Rally seem to be destined to be the forever king sadly. Sad that rally get so little appreciation nowadays though WRC 3 is sure fun. It´s more of a semi simulation though it´s certainly more serious then the DIRT series particularly regarding tracks.
It don´t really cost much. Sure you should get a wheel though you can get surprisingly fast with a joystick but you don´t desperately need triple monitors, cockpits or separate shifters and the likes you need a quick brain and just hate to loose if you want to be really competitive lol. the next gen of the simulations is rolling out but for the current you don´t need much of a computer.