I'm sure what you did was fine. 5 or 6 inches of space is more than adequate. Just make sure your hard lines are flared so the rubber doesn't pop off under pressure. Don't over think it. You'll be fine.
IMO Ford Y’s don’t need an electric pump. I been using the stock mechanical or the 13 years I’ve owned mine with a a 292 and for the last 7 years it’s had dual WCFB quads. The only rubber fuel line is the stock 5/16” from the frame to the pump; I changed it from what was there to a replacement ethanol compatible from Danchuk for a 57 Chevrolet. If my car sits longer than 3 weeks I must crank it 15-20 seconds then pump the foot feed 3-4 times and it starts right up. Normal weekend is one pump.
yeah, you've been lucky. I've had one pop off, it's pretty darn scary to have an engine bay covered with a film of gasoline! Now I make sure there's a flare or bubble or something to keep the hose coming off when the clamp relaxes.
I look at things like this in the context of even though the likelihood of failure is very low, the possible outcome if a failure occurs is so lousy that it makes it worthwhile to take a nominal amount of time to take a preventative measure to lower the risk even more. 99 times out of 100 nothing will probably happen. But if the 1 time it does my cars burns to the ground, then it's worth the 2 mins to flare the line or use a barb.