Re: Starting a SH campaign
Good points. If you're going for a homebrew setting, it may ease some of the pain if you ask yourself at the outset what the two or three most important, world-changing technological changes are. This way, you can restrict yourself to a small set of basic issues (how rubbery is the science of these changes, and how many and how pervasive are their applications). FTL technologies are obvious examples, but the development of nanotech, biotech, energy production, and gravity manipulation are other areas with broad implications--the last two maybe influencing or influenced by FTL technology. Other technologies can be glossed (if you want man-portable laser weapons, maybe you can worry later about exactly how a small, highly-concentrated power source came about) or disallowed (you might decide that none of the core technological developments are likely to produce the power source for a man-portable laser, so slugthrowers or gauss firearms predominate).
Other than that, your big concern is not letting the technological handwavium become the whole of the game--decide what the opportunities for player-character social roles, adventuring opportunities, rewards, and mysteries/plot twists might be as you develop the technology and setting. It's easy to let the tech take over, and the urge has to be managed carefully.