For the first job i would just use less chem and rinse well or just try with your water, i did a retail premises once all clear glass roof it hadn't been done for years and covered in bird muck etc wasn't allowed to use chems on it so was just pure water and they came up fine, it did take allot more scrubbing and water but came good in the end also we were at a height that i was slightly above the glass so could get good pressure on the brush.
Job 2
Again i would try with just water at first and see how it goes, not sure why you think there to high up to spray as its pretty easy to make a sprayer using those hozelock type pump sprayers to reach that high ive made one to reach about 25ft the only thing stopping me go higher is the pole size and length of pole hose, so its not to difficult to spray them if you wanted too.
paul