Yes, it takes longer for a player to switch if their new position isn't one of the ones listed in their coach comments ... no idea how long it takes on average though ... your K was rated 1/2 star in game and 2 star on his page because the rating in-game takes into account player's fitness and consistency ratings as well, and I believe it may also factor in the numerical ratings relevant for their position. So if you have a 3-star kicker for example but he only is rated 1 in consistency, kicking, and punting, his match rating probably won't be 3 stars.

Prolly won't till kicking game gets fluff. I have a solid kicker that I feel should be at least 1.5 stars, but hes not.

remember a key thing is that if your player was high rated at a position to begin with it is going to take a LONG time for him to outclass that position.