I just think that PagerTooltipFormat could have the same possibilities as PagerTextFormat. Catching the ItemCreate event should fix it, but the name of the label can be hard to find. In my case I found that the labels id was "ctl00_ContentPlaceHolder1_rgEvents_SliderPagerLabel".
It has the same naming container as the RadSlider component, which I can find by the following statement;
e.Item.FindControl("GridSliderPager") as RadSlider;
But you line, did not work;
Label label = tc.FindControl("rgEvents_SliderPagerLabel") as Label;
Yes with the Position property you can place the pager at the top or the bottom. But I was interesting in styling the pager by moving only the text part to the right. It look likes you have hardcoded the appearance of the slider, is that correct or is there a way for me to alter the position of the text?