It is better and easier to replace the whole screen replacement. The lcd screen, touch screen and front glass are already bonded together tightly by strong adhesive, so it is hard to separate any one of them just by DIY repair work. Though it is still possible to do that, you may damage the lcd screen or touch screen during the process.
The lcd screen, touch screen and front glass are already bonded together by strong adheisve, so it is hard to replace only one of them by DIY repair work. Though to buy the front glass replacement is cheaper than the whole screen replacement, but it is more dangerous and you may damage the display or digitizer if you just repair by yourself. And it is better to buy the whole screen replacement. But if you still want to replace the glass only, you'd better ask the professional for help.
Here is the video showing how to replace only the s5 glass: https://www.youtube.com/watch?v=PfJ2ap2p... . It seems a little bit complex and ask for the professional skills and repair equipment. It may be difficult for a DIY repair work, and you'd better replace the whole screen including the lcd screen and touchscreen and the front glass.
The verizon usb port is the same as the at&t , but they are different from others like sprint. This blog has listed their differences: http://www.witrigs.com/blog/htc-one-m8-audio-jack-not-work-after-charging-board-replacement/ . The verizon / at&t m8 charging port is here: http://www.witrigs.com/oem-charging-port-flex-for-htc-one-m8-at-t The sprint/other variant m8 charging port is here: http://www.witrigs.com/oem-charging-port-flex-for-htc-one-m8
Did you ever try to open the back panel by yourself? If yes, they would consider that you have broken the phone and made the phone warranty void. Since the mic is soldering on the motherboard, and it is hard to replace by DIY repair work, it is better to ask for the professional for help.