That bearing cap is indeed a very minor thing. I've had those off in the box on quite a number of these heavyweights. They just snap back on. I use just a tiny dab of glue when I do this. The step is the next step up (sorry) on the difficulty list, because two retaining pins are broken. Replacement would involve drilling out the broken pins, as well as painting the replacement to match the old step. Gluing in place is clearly the best solution, as you note.
The antenna is the most serious problem by a wide margin. I can't see how it going to be reasonably possible to fix that. All you can do is make a strenuous attempt at replacing the car a second time, and get a bit more aggessive with Lionel. Have the dealer check the car to make sure the antenna is OK, and and double-check the packaging, before shipping. Remind Lionel of the contents of their limited warranty, which includes defects in materials or workmanship:
"Lionel Limited Warranty Policy & Service -- This Lionel product, including all mechanical and electrical components, moving parts, motors and structural components, with the exception of LIGHT BULBS, LED’s & TRACTION TIRES are warranted to the original owner-purchaser for a period of one year from the original date of purchase against original defects in materials or workmanship when purchased through a Lionel Authorized Retailer*. "
I remember discussion about one of the engineering problems that Dick Maddox was concerned about when Lionel production was shifted to the Far East, and their scale, highly detailed cars began to be produced. That problem, which took a lot of time and effort to resolve, was providing a reasonably robust method of attachment of the detail parts. Lionel found an adequate solution, I think. Detail parts are reasonably well attached to their scale rolling stock. Clearly it's time for Lionel to revisit this issue, at least with respect to their passenger cars and engines.
