This expression most likely originated in blacksmithing, where one hits the high spots on a piece of work to make it look more level (as opposed to being truly level), in the same way that "hitting the high spots" while cleaning your room would make it look less shabby, though not necessarily totally clean.
Yes, it would modify a noun (e.g. spot, mark).
The origin of the phrase is really not known, it seems to have appeared in about 1949/1950
Dad has a secret fishing spot
Dad has a secret fishing spot
Achilles Heel
with its roaring fire
Yes, "come with me" is a phrase. It is a request or invitation for someone to accompany you to a specific place or activity.
"Jiminy Crickets, we are in a tight spot."
Picking flowers, do you love them or not, it NOT a phrase!
The phrase comes from FRENCH.
This phrase pre dates 1950
The gerund phrase "scratching that itchy spot" functions as the direct object of the verb "stop." It indicates the action that the speaker cannot refrain from doing.