http://www.cisco.com/en/US/prod/collateral/wireless/ps5678/ps6521/product_data_sheet0900aecd8031c844.html
The 1242 datasheet says it operates until -20 C
It should be the same for most other access points. Check the datasheet of the ones that you find interesting.
Your 3rd question is a bit strange. WCS is useful to manage multiple CONTROLLERS.
So if you have 30 access points, you are best using lightweight access points and a controller. No particular need of WCS unless you want nice reporting and graphic features.
30 access points would be a pain to manage if you chose standalone access points without controller.
Hope this helps.
Nicolas