\You should not be concerned by the fact that there's a pretty good chance that an A or a K's in the bottom half of the deck--probability takes care of that for you. However, if someone shows you all the remaining As and Ks are in the bottom half of the deck, this should affect your decision.

This situation is a mixture of the two examples I just gave. Limpers are slightly more likely to have an A or K then usual, so it's slightly less likely that an A or a K will flop. However, as it turns out, this effect is very negligible. There was an article in card player a few months (or maybe a year) ago that discussed bunching (which is essentially the same topic), and the guy showed through a computer model that it affected hands by less than 1% even in extreme situations. I'm sure you could find it if you want.