Angels I believe can show up in any shape or form...
If i'm in my car and it breaks down in the middle of no where, a person could come by to help me get my car started again--in a form of an angel...

Angels I believe do have wings, but some angels might not and instead could be in human form.

Angels can, I believe, remotely control or influence a willing human being, causing that person to be somewhere at a critical moment when their assistance will be needed.

Satan and his Wicked Ones can do this also, but instead create death and destruction using the hands of their human slaves.

Before God even created angels He knew He would someday create animals that could propel themselves through an atmosphere of gases on a distant planet. Their wings would be beatiful to behold, an artform even. So it seems reasonable to suppose He used that design motif in creating some of the Heavenly creatures, and foreseeing the useful and beatiful symbolisum wings would represent. As far as we know, angels dont need wings for any practical use. We all know wings dont work in the vacuum of outer space. As for the wings Ellen White saw the children have in one of her visions, I think they were a type of recreational vehicle, invented by the angels for their enjoyment, like we use bicycles and skateboards.

I believe angels have appeared in forms other than human - like canine

My son's girlfriend has a cat visit her whenever she is sick. When she gets well it is nowhere to be seen, and doesn't come into the house, but when she got sick a second time that cat returned to her house and came in and stayed by her bed until she recovered again.

This girl nearly died a couple times (pulmonary clot) etc. I think God has more time for her and may have sent the cat.

Could be

moses was instructed to make the "pattern" exactly as he saw the temple in heaven. the cherubim over the ark had wings. satan was a covering cherub, so that would mean he does have wings.

i read somewhere that we will have detachable wings so i would think that the angels wings could very well be detachable.

as for the "vacuum of space" i dont know that that would apply to angels. we are told they look like lightening when going somewhere. not sure ive seen a bird able to move so fast, perhaps a hummingbird?