BBM
IMO, he did need TLM if he wanted to kidnap a child... because he was all talk, no action and a coward. I think he had secret twisted desires that he revealed only when he found someone in whom he recognized equal depravity - TLM. Without her, I do not think he would have acted on those desires... at least not yet... because he was not bold enough yet. But once he figured out that he could actually voice those perverted fantasies to TLM and that she did not recoil in horror or run like the wind, he became excited at the possibilities that opened up for him... because now he had a puppet to carry out the risky step of actually enticing a child. And all he had to do was sit back and wait for 'his prize' to be brought to him, like the true coward that he is. All just MOO.
And I think he was so driven by his sick urges and the thrill of 'all the good things coming his way' that he wouldn't even have thought ahead enough to realize he would be tied to TLM forever or that he would be entrusting his life to her. IMO, he was all hopped up on drugs and sexual urges and sick fantasies - I don't think consequences played much of a part in his decision making that day. I think he hardly dared believe that his fantasy was going to come true so didn't really have a 'plan'... but once Tori was actually in the vehicle, he knew they had to get out of town, and headed to Guelph for drugs as previously planned. I think the rest of the 'plan' was hatched along the way. I think at some point as they were driving it became clear that Tori recognized/knew TLM - and that's when it dawned on him that they 'couldn't keep her and couldn't take her home'. And also I think that he realized that Tori was old enough and smart enough to identify him, so they had to kill her. And all that happened after that was just spur of the moment decisions... except for the rape, which was what he had dreamed of all along.
All just MOO.