Hair Color Questions

I'm not a pro, but I can't imagine how they could do highlights, then put all over color around it. Seems a lot easier to do it the other way around so you don't have to try to keep the highlights separated out.  Either way, he is the pro, so he should know how to do it over the all over color.  You may want to ask him to do test strands next time though, so he doesn't have to redo your whole head if it doesn't come out right. Toner is used to change the tone of your color (add more ash, etc.), meaning it isn't supposed to lighten or change the color, it just changes warmth vs. coolness in the color you have.  It was probably not toner that he used first, there wouldn't be a reason to do that, so it was probably something else.  It probably was toner the time you called it toner, the second time.

It doesn't matter how soon you go in really.  Its an excellent idea to wait a couple of days to let your scalp put out some more of its natural oil.  This protects the scalp from the chemicals.  You may want to wait a couple of weeks if your scalp got irritated the last time you had it done, the purpose of that wait being to let the scalp heal.  It makes no difference at all to the hair.  However, since your hair is thinning, you may want to consider whether you want to keep doing chemical processes to it, as any of these chemicals will cause a bit more fallout than you would naturally have.