I think you're confusing several arguments here. At most clubs in the UK the forward tees are for Ladies & Juniors and the white tees are competition tees leaving the 'general' mens tee as the yellow (although some clubs let members and members guest play from the white tees at any time if they wish).
So, if a junior is just starting out he would play from the 'junior' or 'forward' tee. As he progresses and achieves a handicap he would move to play from the mens (yellow) tee. Here is where the handicap system comes into play. If a junior is just getting going his handicap will reflect that and he will be given shots over his competitors (other juniors or older men). Then as he progresses his handicap will come down (but it will be based on play from the 'mens' tee - what else could his handicap be based on !).
