I will also jump on this free respec. I have made a few mistakes with my first characters and never could afford a respec.
I now start to understand how the stats work so I would like to comment on Telekenisis question. I made one of these guys and really like him. The caster energy feedback with melee finisher fits me well.
For a Telekenisis build, what would I best be taking going through missions when it comes to rewards?
Per default Dex(crit) and Ego(crit bonus) are the only stats that will increase damage. Str will to a lesser degree for melee characters but it is unclear to what degree. I suppose this is valid for Telekenisis melee attacks as well but I am of course not sure. Besides Dex and Ego you will increase your damage by investing in your two superstats. If those two are Dex and Ego that will, for most classes, maximize your dps. However some powers(attacks) may scale with other Stats, for Telekenisis it used to be Endurance (according to the powers' help text). We will see if this has been changed to Ego in this patch. If not Endurance is also a good choice for a superstat in a Telekenisis build. For levelling I think picking Recovery, Endurance and Constituion are good stats since it will make it easier to survive and hence faster levelling. For example, if Constitution is a superstat you will not only increase your hit points but also your dps.
If I got something wrong I hope the more experienced super heros will correct me.