Learn English – “On mind” vs “in mind”

As to the main point of your question, you should use 'conscript', since 'conscribe' actually has two meanings, and is not nearly as common. (This spell checker doesn't even recognize it!)

The preposition could be equally either. 'Conscripted into the army' makes just as much grammatical sense as 'conscripted for the army', although the latter puts a slightly higher emphasis on the 'army' than does the former; just because 'for' is more of a Preposition Of Interest, and draws one's attention to its object more than 'into' might.

When you say "mind" you are saying "be aware of" or "be careful with" not to be confused with "beware of".

They might overlap, depending on why you may want to be aware of something. You might need to "mind the dog" because he bites or you might need to "mind the dog" because you are about to absent-mindedly step on it's tail.

"Beware of your head" is strange sounding. "Mind your head" means to be careful with your head. "Beware of" in this context implies that your head is going to do something bad to you, whereas "mind your head" is meant to say be careful not to let something bad happen to your head.