You can use the dry cover for the topping, that way you don't have to wet the scarf to remove it. You said in your original post you used tearaway, that's why your letters and the outlines aren't matching up. The fleece is stretching, as soon as you stitch the outline for the letter, the tearaway starts perforating. allowing the fabric of the scarf to move around on the stabiliser. That's why I suggest using a sticky back stabiliser, it prvents that happening.
Another thing you can do is cutout your applique shapes first, to save writing a lengthy description, visit this link applique quick and easy
I use this method always, so much faster than trimming in the hoop. Don't worry if you don't have what they call dielines, the first tack down line of an applique design acts as one, then you simply repeat it on the scarf to use as the placement for the shape. This wont make sense until you have read the instruction sheet on applique.
It seems like a longer method, but believe me, it saves hours of trimming and frustration. If you want you can use the top thread colour in the bobbin so you have that on the reverse of the scarf,