Welcome to the forum samarka.
90s should be the right bocks for you
you should get those. As for your height there have been tall people on bocks before. Tok comes to mind
the bars extend pretty far but if it isnt enough you can wear them lower. Some people do it by choice. You cant go too far. with bars we say just below the knee. You can go a little way below that. Cuffs are always worn a bit lower. Its too hard to desbribe. Theyneed to be a decent height probably within the top 1/3 of your lower leg. Anyhoo. I think you will be fine.
Calf cuffs come with bars. Not sure about this unrestricted movement thing but they are deffo more comfortable and easy to get secure. If anything its quite the opposite to what you are thinking. Bars can allow your legs to wobble about. Cuffs eliminate this pretty well and support your legs as well as the cuffs. No more strains on ankles ect. I think less. Because my legs are secure in cuffs i dont need to have the foot straps so tight they cut off blood circulation to my toes
nobody really wears skate pads. Not on knees anyway. The 661s should be ideal. Kyle straights are the ones bockers use. If they are like that then they should be ideal. Most people use knee/shin pads because they go through the bars and provide more support. Plus bars and cuffs can stop normal pads sitting right.
Hope that helps a bit