Fish fert is mostly for N and N is to induce greater vigor. When trees are small, I like to get them to size as quickly as possible but once they are bearing meaningful fruit I am careful to not overstimulate vegetative growth with excessive N- damaging fruit quality and making trees and fruit more susceptible to pest problems. Fall fertilization is not dangerous and is actually helpful to get N to the buds before mid spring and get growth to most vigorous start. It is late summer N that can sometimes postpone dormancy and hardening off that protects trees from winter damage. This danger is highly exagerated in the literature in my opinion as you get exactly the same results here when we have early summer drought and then soaking rain in mid-august. Some trees do get a late surge of vigorous growth which itself can suffer winter kill but by my observation the rest of the tree does fine. I'd be curious of the observations of others on this point. This is one of many observations I've made over the years that makes me ever vigilant to expert BS even as I continue to go to pedigreed experts for certain kinds of advice. Speaking of the advice of pedigreed experts, Cornell recommends a general application of 2 pounds N per 1,000 sq ft annually for general orchard maintenance if you are not doing a soil and tissue analysis kind of program.

All your type two clematis should be treated as type III clematis for the first year or two after you plant them. That means each winter/earlyspring they should be cut back to within a few nodes of the ground. As they come up, you can pinch the growing tips out after 4 to 5 leaves have developed. After having done this the first two years or so, I would not be pinching them out since they bloom on older wood and you might be pinching out blooms. Of course don't know if you can do this in your zone or not since I don't know the length of your growing zone, but in my zone I treat all my type IIs as type IIIs and hard prune them all every winter. I have Proteus, Piilu, Sunset, and Blue Light all up and over 4 feet tall after treating them as type IIIs last winter.

All thoughts welcome, thanks! Since you said "all thoughts" I figured I'd tell you that the other day I joined flickr so I could host photos and I came across a group for people who grow Stapeliads and Asclepias. If you get a second check them out or I could post to the group for you and ask your question for you and see if some of those growers have an answer? (if the thread doesn't go beyond the helpful advice S&B gave)

Keeping the feeders out won't make them stay all winter but suddenly removing the food source may leave them at a disadvantage. My dominant female seems to feed constanly now and she never goes far. Any time another hummer arrives she is quick to send them packing. I assume that if she stands guard here all day, she may not have an alternate food source.