Tim, here are the answers to your questions and a few more pieces of information you should have before you make your decision....
At 75 mph the motor is turning at around 3700 rpm.
The hardtop stays in the garage. The soft top rolls up and can fit in the trunk. Some have suggested it can fit behind the seats but I have a small subwoofer back there that prevents this from becoming a reality.
I have use the car in 25 degree weather and have found the heater to be perfectly adequate. In the hot south texas heat the a/c is very anemic. The windshield stays fog free, as does the rear window. Note that there is not rear defogging heating element like on most cars (I haven't found it to be necessary either).
The paint and fiberglass won't be affected by the salt any more than any other car. The aluminum, reportedly does not do well with the oxidizing effects of salt. i don't have any personal experience with this, though. The starshield does not cover the entire car, just the areas prone to rock damage.
Now for the questions you didn't ask:
1. The car creaks and rattles, and the windows and trunk leak in heavy rain.
2. Many of us have put on an aftermarket exhaust. These tend to be louder than the stock exhaust, which very likely was on the car you drove.
3. The car can cost a lot to insure if used as a DD. Without any tickets or accidents, by insurance costs tripled from what I was paying on my Infiniti G35 coupe. Also, many insurance companies won't insure it because it's considered an exotic. These cars are easily totalled because Lotus specifications dictate that any damage to the aluminum frame is not repairable and therefore, the car is scrapped. Be very careful if you are buying a used car. Some have been repaired with a clean title even though they should have been salvaged. When in doubt have a Lotus mechanic go over it. Proper inspection of the frame requires the removal of both clams.
4. Speaking of clams, a damaged clam can cost 11-14k to replace. They are often repairable at around a tenth the cost, but replacements are expensive.
5. Windshields have taken a long time to obtain and can be very expensive to replace.
6. These cars do require extra maintenance compared to your standard Talon. Some regularly check the torque of the suspension bolts, especially in tracked cars. A few of us have had problems with some suspension bolts loosening and breaking during hard cornering (I am one of those people).
7. Dealer support and service quality varies WIDELY, if you are not mechanically inclined I would carefully consider what kind of dealer support you have in your area.
8. If you are buying a used car ask for an ECU dump. The ECU in our cars records copious amounts of information that Lotus has used to deny warranty claims. If in doubt, post the ecu dump and we can tell you if it contains any concerning data.