PHOTOS

I would like to paint these cabinets white. However, the tenant attempted to put some kind of gloss on half the cabinets because the cabinets looked unfinished. The tenant did not remove the cabinet doors before applying whatever she used and a few of the cabinets have dried drips left behind.

Someone on another forum suggested that a liquid deglosser (such as the brand Heirloom) is appropriate for cabinets in this condition (meaning I don't need to sand). Sounds too good to be true. Are they correct or should I sand first?

(Some cabinet doors/drawers, as the ones in the first photo, will have to be replaced entirely but this is to show the condition of the finish I generally have to work with on the good cabinet doors... The fourth photo actually shows what the cabinets look like that she didn't gloss.)

Also, can anyone tell if these are oak cabinets or not? I'm not sure if it will make a difference during the painting process but it's probably a good idea to know.