Hi, Pippi. Sorry this call for help got lost in the shuffle. Removing dried leaves can't hurt. I would use the granules rather than the liquid, unless you use the liquid at half-strength. Manufacturers tend to advise the use of too much fertilizer because it's in their interest if you use it up quickly and have to buy more.
Yes, some people do prune type 2 Clematises in fall. See how it looks then. I usually wait until spring for the type 2 vines, but it's possible to do it in fall.