Nope, i know the whole reason whats PIE etc, but the reason isnt related to it. 5.0+ should just use gdb from termux and older android could use gdb from Dan's. I've tried some hacky build for support 4.x and it really sucks, Why bother to force termux to useable on <5.0? thats the reason. You...
idk what you mean. But termux has a package manager system which android didnt has it out of the box. There's no downside even if you have it installed anyway. It has many package to play with soo.. termux-packages/packages at master · termux/termux-packages · GitHub
Android SDK has builtin emulator, development kit standard should be enough used for debugging purpose. Or just bake a custom rom from android-x86 project, thats what i'm doing anyway.
Well, now i wont bother to spoonfed to a guy pour some salt to me in the first place. My advice is that you need to read and know what the text means before complain.