Well, usually you don't merge from a stop, but off a 30mph zone. there's also usually more than just the merging lane to accelerate, if you accelerate on-ramp you can easily be doing 50 when reaching the beginning of the merging zone. Slipping in between trucks and taking it from there shouldn't be an issue. Neither should accelerating another 20-30 mph. You can readily take advantage of the lower weight of the car when cornering on the ramp. Also, Fords are usually decently sprung, so that you won't feel like you're on a boat.
Also, in civilised countries, people leave - and even actively create - spaces for merging vehicles. Here in France people do 130 km/h on the Autoroute. Yet trucks and decrepit 20 year old diesel renault 5s can still safely merge, as people obsessively free the right hand lane for merging traffic.
If there's only a single lane you're merging onto, and people are doing 75mph ...there's a problem in the system. Single lane merging usually happens around a maximum 50 mph allowed.
Currently the image I get, is that you are afraid because the rule of the road is the same as that of the economy: the strong eat the weak. Can't afford to be weak, or somebody will crash into you out of spite. This distrust of others is something that does seem to characterize the American Dream. In Germany, it's probably not that dissimilar, with the rule of the Audi and BMW on the left lane, expecting you to hop out of the way, when they come at you on the speed limiter at 150 mph.
In Southern Europe though, while rules aren't being respected, there is more of a respect of other traffic participants. It looks more chaotic from the outside, but usually people leave you the space you need, and are somewhat less aggressive than some German drivers. Driving the French Autoroute is Zen. Driving the German Autobahn (during anything but lowest traffic, going faster than 50mph) is a nightmare. Driving the Swiss highway system is hell (mostly because you have to maniacally stare at your speedometer, while in often dense traffic, that refuses to go below the speed limit, even if security distances are around one twentieth of what they should be).
Aaaanyway, to get back on topic: It seems to be a cultural insecurity issue, that's preventing America from downscaling their vehicular demands.
Maybe a gradual change can happen, but it's unlikely, as especially in crowded areas, more people will feel that insecurity, and cling to their ridiculous vehicles.