First thing I'd do is get rid of anything that's growing and touching the window. Then I'd figure out how much you want height wise to cover the window and shape it from there.

Hope that helps some!

I am pretty sure this is a chaste tree. You can find pruning advice here: https://www.thespruce.com/chaste-tree-growing-profile-3269206#toc-pruning

In short, cut spent flowers now if you want more whenever the go brown. In winter, cut as much off as you want, even back to the ground. If it causing problems (like hitting the window) now you can cut those parts immediately, but I would wait until winter to do a hard cut.

You can use pruning shears or trimming shears or electric hedge trimmers. Always wear goggles, a mask or bandana over your mouth is also recommended.

Beyond all the leaves is a section of barren stems, if you go that deep then you've gone too far. You want it to be wide in equal directions from its base. Hedges can be trimmed any time of year if they get enough water, even if they become stressed they can usually bounce back all on their own after a period of dormancy.

It's a butterflybush. Just cut it back to where you want it to be. They are extremely hard to kill.

I'd use some heavy duty loppers.

Start from the back, round out the shape, but make sure to not cut more than 1/3 of the plant within 3 months of each trimming.