which parts are you talking about
A.Fiber optics are the best option. Because of the fact they transmit signals as light instead of current, fibres are immune to electronic magnetic interference(EMI) and to radio-frequency (RFI). We can connect the fiber ends to the 10BaseT networks by switches, to the design shop and other end to the front office. Since it's optic based, signals from the shop floor can easily be carried where EMI and RFI are enormous. Shielded Twisted Pairs can also minize the interference, but is not recommended, because they are not close to efficiency in comparison with optical fibres.
B. The 10Base5 Coax cable is a good choice for question 2. It is 500 m long and also less expensive. However, the downside is that it is an old and interferential technology. Multimode fiber with maximum data rates of up to 10 Gbps per second over a 600 meter distance may be the other best choice. So, either fiber optics or 10Base5 are available to you.
C. In the elevator shaft, we can use RISER CAT6 cable or 802.11n Wireless Access Point. The second part says of the "higher speed" requirement, so that the WAP of 802.11n is obvious. RISAR CAT6 or Fiber Optics (if we look for any interfaces in the elevator shaft) can be the best choice.
Please see attachment for differentiation.