Question #1 - Does anyone know if any US autos/trucks are still manufactured with the high beam switch on the floor?
Question #2 - If there are none made now, anyone know the last year/model that had the floor switch for the high beams?
None now, for sure. My '72 Duster had that. When it went away? Beginning in the mid to late '70s?
That’s probably about right, tex. First car I had with it up above was a '78 Fairmont.
(Kept getting my foot stuck in the steering wheel.) 
ans. to #1 - no
ans. to #2 - by mid 70’s I believe most cars had controls on the “stalks”. Likely last to convert to hand controls would have been pickup trucks, and full sized vans. Not sure when PU’s moved to hand controls.
Ford pickups kept the switch on the floor through 1991.
Cars stopped long before that with the 1980 Granada and Pinto still having them.
I used one of those floor switches to turn on the fog lights I added to my 92 Explorer.
There’s a public notice from the Oklahoma Govenor’s desk on display at a local key shop stating that by such and such a date all beam selector switches must be relocated to the floor to conform with a new state statute that promotes safety.
According to the notice, there are an excessive number of automobile accidents being caused by drivers who get their feet tangled in the steering wheel while attempting to flash their headlights after each University of Oklahoma football win and the state has decided to end this deadly practice.
It looks legit anyway. 
I thought I preferred having the beam selector switch on the floor until my wife broke her foot. When she would drive at night while I would try to get some rest, I would almost be asleep when I would hear "tappa-tappa-tappa click click and then another “tappa-tappa-tappa click click” . My wife was working the beam selector switch with her crutch.
I don’t think I want to move to Oklahoma. My wife might break her foot again and I would have to have a vehicle with the beam selector switch on the floor.
Our 1964 Model 62 Caddie had it, and also had a radio seek button on the floor. Amazingly, I never mixed the two up. I think my 1970 Chevy Malibu and my Mom’s 1972 Impala also had the dimmer on the floor.
My brother had a 1977 Cadillac Coupe DeVille and the dimmer switch was on the floor. My 1978 Oldsmobile Cutlass had the dimmer switch on the column. I think the first car I remember with a column dimmer switch was a 1971 Pontiac Grand Prix.
My 68 Dart had it but my 74 Olds did not. They used to rust up pretty bad from winter slush on the floor.
My '67 Mustang had the foot button for high beams and a small petal to shoot windshield fluid and activate the wipers to wash the windshield. Got those confused sometimes got a shot of fluid when I wanted high beams.
I once owned a standard shift 1954 Buick. It had the brake pedal, clutch pedal, accelerator pedal, parking brake, dimmer switch and a floor button to move the selectronic radio to the next station all on the floor. The starter switch was combined with the accelerator, so even the starter switch was on the floor. Even a pipe organist doesn’t have that many pedals to worry about.
Once up on a time there was no such thing as power steering. Then, PS was an option and many cars on the road still had manual steering. These cars had foot controls because you needed two hands to steer and real muscles to park a car. Once all cars had power steering drivers could handle more controls with their hands and the buttons on the floor disappeared eventually.
Estimate in the 40’s about 10% of cars had PS. That went up to about 50% in the 50’s, and 75% in the 60’s. In the 70’s buying a new car without PS was rare. Cadillac I believe put PS on the 1st production car in the late '20’s or early 30’s.
Nothing that I know of has a control comming out of the floor board by the driver’s feet. In addition to the rusting problem, it seems to me it makes it much harder to seal the floor from possible fumes, especially in traffic while idling. My Toyota has the fuel tank release on the floor but it seems to exit through the side frame. IMO, there will be another change as shifters eventually move “back” to the dash area too. With everything operated by electronically, why not ?
I remember by Dad’s '72 'Cuda had the hi-beam switch on the floor, as did his '75 Dodge Maxi-Van. My '70 Fiat had the control on a hand stalk as did my '78 Dodge (Mitsubishi) Colt - neither the Fiat rnor the Colt had power steering. The last vehicle I remember that had a foot switch was my '84 Jeep CJ-7. I’m pretty sure Jeep moved it to a hand stalk in '85 when they changed to the “YJ” or Wrangler model.
My 1977 Lincoln Mark V had the high beam switch on the floor. My 1962 and 1949 Cadillacs have the switch there as well (and the '49 has a push button on the dash (near the key) for the starter). I remember a 1978 Mercedes 300D that my parents bought new being the first car I drove with the high beam control on the stalk.