you seem to be under the impression that space is a hard vacuum it is not, modern observatories including space ones have hinted that there is a lot of space dust that hasn't coalesced into larger bodies. there are a lot of small, medium, and large space debris in the way. without a force shield even if the warp drive disintegrates the small stuff a pool ball sized debris is going to be rather like an atomic blast no force shield no ftl travel. and if people are going onboard they are going to have to do something that hasn't been done in a long time, have a stable pool of healthy reproducing children unless of course we simply use robots up until we 'seed' planets with cloned human beings.
given the age of the universe as measured by xray telescopes it is quite unlikely that life didn't evolve long before humans came around, and that those beings could have developed technology to seed the universe and had their planets freeze up or burn up. as the galactic habitable zone shifted through the years.