[geoschmo]

The cylons following them isn't so much of a problem. You don't need to bring the whole fleet. Once you've scouted the planet with raptors or whatever, you simply have one ship jump a different distance and off a few degrees. The ship drops off a hundred or so people and rejoins the fleet at a predetermined coordinate later on. Anyone tailing the fleet isn't likely to notice anything.

Space is really big after all. It should be very difficult for the cylons to find these colonies. Unless they can simply jump into a system and listen for radio signals or something. If they have to look for habitable planets and then carefully survey each planet it would take forever to find them. Even if they found the planets they might not find the people.

The concern about infiltrators is valid though. If someone is feeding them info about where to look it would be quite easy to go after them.