"If i put a dado blade on what will happen to it?...."
Ok Tom you go out and spend 80 odd quid on a dado set. Get home, pull the regular blade off your TS, put on the outside blade of your dado set and............well, that's it really. No more room on the arbor for anything else other than the arbor nut, and a total waste of your 80 dabs. I think you need to become familiar with stacked dados and compliant arbors to appreciate the ins and outs of the issue. I appreciate that we all have to do extensive research before such a major purchase such as a TS but I think you have to decide exactly what your requirements, desires, needs etc are before you purchase, especially as you are at such an early stage in your WW hobby/career etc. We've all been there Tom, so appreciate your dilemma. So, to this end, if you want me to, I will post pictures of a dodo compliant arbor, dado set, how it mounts etc. Let me know.
Good luck.
Noel