UFO mess ups

Say what you will, they are here for peace, they want to take over the planet whatever unless i meet one and ask them i don't think anyone knows what heck aliens want. I'm highly interested in the military and from a military point of view there is something up with UFOS.
If they are capable of great speeds, why would they hover or glide?
If they are hostile, why show yourself?
Isn't it weird that with such technology as color changing, camofluage, invisiblity, stealth that these aliens are reported to have that they would be so easily seen?
In abduction cases the abductee most often remembers thru regression therapy, wouldn't it just be easier for the aliens to kill the person instead?
If there purpose is to help why not land on the white houst and come out bearing gifts?

They hover and glide so they can slow down, observe, stop, and take off again. Are you going 100km/hr from the moment you sit in an automobile - and then never change speed ever again. What do you do when you approach, then reach your destination?

Some are hostile, others are not. Those that don''t show themselves do not wish to be seen.

Some of these technologies (cloaking, etc.) they may have, some not. And who says they are "...so easily seen". I haven't seen one yet - at least I don't think so... Have you? Know anyone who has? get my drift? Please explain how you conclude that "...they are so easily seen"? Seen, they may have been. Easily, not.

The purpose of an abduction is not to kill the abductee.

Who said their purpose is to help? Even if they can and would like to, perhaps they can not (the Prime Directive, etc.). IMO The head of the US government is one of the least likely place to make their presence known, to help or otherwise, and the occupants of said house are probably the least deserving of any 'gifts' that may be forthcoming. A university, think tank, neutral government, or benign governemnt agency specified with this task would likely be a better choice.

WHy abduct at all? THey can travel interstellar distances, run around butt naked in our biosphere without getting sick, (we can't even go to another continant let alone planet and not get some sort of pathogen) , can float through walls, trick out govt. with bad treaties, but they know less about basic biology.

Why abduct people. I got a better idea.
Step 1-Wait for them to go to work.
Step 2-Sneak into their house, probably where the wall transmogrifier ray will come in handy.
Step 3-Jack some hair follicles from their bed pillows.
Step 4-Sneak back out.
Step 5-Go back up to your spaceship lab.
Step 6-Read the whole human genetic code.
Step 7-Make clones with their DNA modified to suite your fancy.

All you would need is the basic genetic code for humans and voila.

We can pretty much do this so why not them. Dont tell me that our scientists have to go hold their little zetan hands when they attempt this.