What is the ruling on the fashion of raising and volumizing the hair at the front of the head, and is this considered imitation of disbelievers?

It is permissible to style hair in any manner that adorns it, as long as it does not involve imitating disbelievers or transgressors, or men imitating women and vice-versa. If a particular style becomes widespread among Muslims and no longer distinguishes disbelievers, then there is no harm in it, even if its origin was from them. It is advisable to spend time on what is beneficial and not let fashions be the primary concern.