Hi,
The LPC55S14JBD100E is a powerful processor, it is okay to select it.
For your questions, I will answer you one by one.
This is link of LPC55S14:
https://www.nxp.com/products/processors-and-microcontrollers/arm-microcontrollers/general-purpose-mc...
1. IDE
>>>It supports MCUXprssso tools(from NXP, free of charge), Keil(third party), IAR(third party)
This is MCUXpresso tools link:
https://www.nxp.com/design/software/development-software/mcuxpresso-integrated-development-environme...
2. Software libraries
>>>You can download SDK package from the link:
https://mcuxpresso.nxp.com/en/welcome
3. Trust zone
>>>>Yes, the LPC55S14(with "S" prefix) supports trustzone feature, the SDK example provides trust zone example
4. Stacks
>>>The SDK provides the usb stack
5. SDK 6. Debugger tools
For the debug, you can use the "MCU-Link Debug Probe", "LPC-linkII", "MCU-Link Pro Debug Probe
This is the link:
https://www.nxp.com/products/processors-and-microcontrollers/arm-microcontrollers/general-purpose-mc...
7. Does it support segger tools?
Yes, the Segger tools supports the LPC55xx.
Hope it can help you
BR
XiangJun Rong