Well, my mother wouldn't do most of the E-night rides, but your mom might -- I plan to do them when I'm 72. They are Space Mountain, Splash Mountain, Big Thunder Mountain, Country Bear Jamboree (show -- not a thrill ride -- and my mom likes it), Alien Encounter (not a coaster but kind of scary -- my mom wouldn't like it), Buzz Lightyear (ride that's like being in a video game -- you have blaster and get a score at the end. My mother would ride it but would not "get it"), Haunted Mansion (she ride its and loves it), Astro Orbiter (a kiddie-like flying ride that is way up in the sky --- she would not ride it), and Tomorrowland Transit Authority (track tour over Tomorrowland and through some attractions -- my mom would like it).
There also generally are lots of characters out on E-night, but there are VERY FEW shops and restaurants open.
The monorail goes to MK from the Transportation and Ticket Center (i.e., the parking lot).
We always use Disney transporation for E-night, but there's nothing wrong with taking your car if you want. Just remember that you can't actually take the car to the park. You park at the Ticket and Transporation Center, then ride the monorail or ferry boat to the park. We never do this b/c we arrive at opening if it's first thing in the day or arrive by monorail if we're coming from Epcot or by bus if we're coming from another park.
I have no idea whether you can take a taxi -- why would you want to?.
Fireworks per se are only at MK. Epcot has Illuminations and MGM has Fantasmic -- both are very different from each other and much more elaborate than MK's fireworks.
