My question is, can Tae Kwon do compliment AIkido? Thanks
Incorporating knowledge of other styles into aikido training is a pretty common question. In practice, I don't think it works out in most cases. A necessary condition would seem to be a solid understanding and competence in at least the basics of the style in question, and then there's the question of the style itself. It may be that your junior black belt program was something exceptional, but most youth martial arts "training" is just another kid activity, and I'm afraid TKD is notorious for decorating kids with grandiose and overinflated ranks and not instilling any actual martial skill. If your school was one of the few where you spent considerable time working out on the heavy bag, and sparring with hard contact, you may have learned how to land a solid punch or kick. If, on the other hand, your school emphasized WTF-style "sparring" (read: lots of tap-tap high kicks and essentially no punches, because punches to the head are illegal and punches to the body never get points no matter how well they're done) and poomse, I don't think that's what I'd want to base my atemi on.
But even (especially?) if you can punch like Ali and kick like a mule, it's iffy to go off script in partner practice, unless both you and your partner are skilled enough to train like that. I'm reminded of seeing a newbie in his very first jo class, take a swing at his partner with a speed, strength and enthusiasm that was inversely proportional to his level of skill and control (oh, such a bad combination). His partner was considerably more skilled, able to not only protect herself from the wild strike, but to continue to the next part of the kata without using more speed or force than the newbie could handle, and so no harm done -- but Sensei saw this, stopped them, and said to the newbie, "Don't dish it out until you can take it." As someone once pointed out in these forums, the speed and strength and intensity of your attack tends to bounce right back at you -- that's the nature of aikido. Unless your partner is pretty skilled, the danger of punching like Ali and kicking like a mule is, first, that you'll hurt your partner; second, that your partner will hurt you. Same goes anytime you go off the script. Until you and your partner both have the skill to color outside the lines, better stay within them.
As for kicks specifically, I asked my sensei about that, and was told it's for two reasons: first, not many people are competent at kicking (including most who think they are), and second, the ukemi is difficult and it's easy to get hurt. Looking at the big wide world out there, kicking seems like a low percentage attack to defend against, and if we did train against kicks, I think it would make most sense to deal with kicks at knee level or below, since that's the highest most fighting dufuses seem capable of.