I haven't really seen any difference with my snakes when it comes to grabbing them from the top VS from the side. But a BP that is scared will try to defend itself no matter where you come from.
If you want to have a glass tank, go buy a terrarium, and not a aquarium. The terrarium is better for humidity and makes everything more easy!
Other issues with a glass tank? Well the humidity and heat control was enough for me to stop using glass tanks.
The glass tank can also make the snake shy, and afraid. And that can make a snake stop eating. Just make sure you have two hides. One on the cold side and one on the hot side.